Tsuna is the only child of Iemitsu Sawada and Nana Sawada. He grew up in Namimori and first met Timoteo as a child. During this visit In the anime, Timoteo felt Tsuna's potential and temporarily sealed Tsuna's Sky Flame with hope there's no need for Tsuna to be involved in mafia business.
For the next several years until he was in middle school, Tsuna lived an uneventful life before Reborn's arrival, where he greatly admired Kyoko Sasagawa, who was the first girl to ever speak to him.
One day, an infant hitman named Reborn comes to Japan from Italy in order to train Tsuna for the role of tenth Vongola Boss. Tsuna was chosen because he was the great-great-great grandson of the First Vongola Boss, who had moved to Japan a long time ago.
When meeting up with his crush Kyoko, Reborn immediately noticed that Tsuna had feelings for her and asked if he ever confessed his love to her, where he reveals to have never confessed due to her being the most popular student in school and having the status as a loser. Reborn shoots Tsuna with a Dying Will Bullet, which sends him into Dying Will Mode, where he is forced to confess his love to Kyoko, who is scared away. When he arrives at school the next day he's teased by all of his classmates for confessing to Kyoko in his underwear, where he is challenged by Kensuke Mochida, who is disgusted by his behavior towards Kyoko and is challenged to a Kendo match. Tsuna decides to flee, rather retaining his status as a loser, but is stopped by Reborn who has been watching Tsuna to make sure he conducts himself as a true Mafia boss, he once again shoots Tsuna with a Dying Will Bullet, and Tsuna returns back to fight off against Mochida, Tsuna breaks Mochida's kendo, headbutts him, and tears out all of his hair, making him the winner of the match.
Kyoko is amazed by Tsuna, revealing that she believes that his previous love confession was merely a joke, and the two become friends.
Sometime during school, Tsuna is introduced to a foreign exchange student from Italy named Hayato Gokudera. Hayato is fully aware of Tsuna's status as the tenth boss of the Vongola, and acts hostile towards him, refusing to accept that Tsuna is the boss. Hayato attempts to kill Tsuna, deeming him not worthy to be the boss, though fails in an attempt to use his Triple Bombs technique on Tsuna and is almost killed. Tsuna enters Dying Will Mode and saves Hayato's life, sparking a devotion to Tsuna and aiming to become Tsuna's right-hand man. Tsuna attempts to persuade Hayato to simply be friends but is too afraid of him.
While playing baseball with his classmates, Takeshi Yamamoto picks Tsuna to be apart of his baseball team, much to surprise, though he causes the team to lose and is forced to put away all equipment. Takeshi decides to help him, where he explains that he's looking for ways to improve on his baseball, Tsuna lies and tells Takeshi that he should just improve more and he'll do better. When Tsuna arrives at school the next day, he's informed that Takeshi is attempting suicide after breaking his arm and believes that he'll never play baseball again. Takeshi calls Tsuna arrogant after his recent victories against Mochida and the volleyball tournament, which Tsuna quickly denies stating that he only gave Takeshi that advice because he never actually worked hard for anything before. Tsuna enters Dying Will Mode to rescue Takeshi from falling off the school roof after that Takeshi lightens up and becomes friends with Tsuna.
Tsuna also started to bond with his crush Kyoko, becoming friends with her and making a girl named Haru Miura have a crush on him after she falls into a river and he saves her from drowning.
Students from Tsuna's school started to get attacked by an unknown group, and Tsuna was assigned to find and to defeat them. When he found that the Gang attacked based on Futa's ranking of the strongest people in the school, he realized that Hayato was their next target. He quickly ran to warn Hayato, only to find him having already beaten Chikusa. Chikusa, having figured out that Tsuna was the Vongola Boss, quickly attacked; however, Hayato protected Tsuna causing him to get severe injuries. Chikusa continued to attack Tsuna, only for Takeshi to step in and forced Chikusa to retreat. They then took Hayato to the school hospital, and Tsuna blamed himself for not moving in time, forcing Hayato to protect him. Reborn then told him that the group was Kokuyo Gang, a gang that was exiled from the Mafia and had escaped from prison. Reborn then read a letter by the Ninth, which told him to destroy the gang or face death.
Tsuna leaves with Hayato, Reborn, Takeshi, and Bianchi to the gang's hideout. After defeating Ken, M.M, and Birds, Futa then reveals himself and states he now follows Mukuro, causing Tsuna to follow him in the woods. He then meets Mukuro, who claimed himself to be one of the hostages. Tsuna was at first didn't feel anything from him until Mukuro suddenly questioned about Reborn, prompting Tsuna to return to his friends to find Lancia, who everyone thought is the real Mukuro, eventually beginning to fight him. Tsuna then enters Dying Will Mode and defeats Lancia after a hard fight; however, after the fight he states that Lancia is not evil, surprising Lancia, that he tells Tsuna that he is not truly Mukuro and that Mukuro has messed up his life. Lancia is attacked by Chikusa, only furthering Tsuna's hate towards Mukuro.
They next entered the main building where Mukuro is and is met by Chikusa, to which Hayato stays behind to fight Chikusa, allowing Tsuna and company to leave. They meet Futa, who attacked Bianchi, with Reborn stating that he is being controlled. Tsuna is able to break Mukuro’s control of Futa, causing him to faint. Mukuro then attacks, showing Tsuna is hopeless and outclassed until Hayato comes in with Hibari. Hibari then continues in Tsuna place, seemly defeating Mukuro, only for Mukuro to wake up, and shoot himself. Bianchi wakes up and attacks both Hayato and Reborn, with Reborn realizing that Mukuro shot himself with a special bullet, that allows him to possess anyone that has been cut by his trident. Mukuro then attacks Tsuna with Hayato, Bianchi, Chikusa, and Ken's bodies.
Tsuna realizes that Mukuro is pushing the bodies to their limits and not caring, and he begs him to stop, only for Mukuro to reveal his plan is to take Tsuna's body, to control the Vongola, destroy the Mafia, and start a world war to destroy the world. Tsuna, feeling desperate, asks Reborn what to do, and Reborn states, do what you feeling tell you to do. Tsuna then states he wants to beat Mukuro, causing Leon to create the Rebuke bullet and the X-gloves. After being shot by the bullet, he hears everyone rebukes him, transforming him to Hyper Dying Will Mode and his X-Gloves to their combat mode, allowing him to defeat Mukuro. He then hears Mukuro’s past from Ken and Chikusa, causing him to lose his hatred of Mukuro, and feels sorry for all three of them when they are taken by the Vindice but is happy when the Vongola arrive and provide medical attention to him and his comrades, till he collapses from pain of entering Hyper Dying Will Mode.
While shopping, Tsuna encounters Basil, an agent of the CEDEF, as he was attacked by a swordsman. The swordsman was revealed to be a member of Varia, whose leader, Xanxus, attempts to become the 10th Vongola Boss. With the Varia targeting them, Tsuna and his chosen Guardians train with their own tutors for the next ten days in preparation for the Varia's arrival. It is revealed that Tsuna's father, Iemitsu, who was revealed himself to be head of CEDEF, picked Tsuna instead of Xanxus as the Vongola Boss, and as such, the candidates for the next Vongola Famiglia had to fight against each other for possession of the Vongola Rings. Knowing how strong Xanxus is, Reborn decided to train Tsuna to master Vongola Primo's technique: Zero Point Breakthrough.
During the Lightning Ring Battle between Lambo and Levi A Than, Tsuna was disqualified, as a result of saving Lambo which was prohibited, and was forced to give up the Sky Ring. After the Cloud Ring Battle, Xanxus sent the already defeated Gola Moska on a rampage, and Tsuna was forced to destroy it; however, it was revealed to have been powered by the captive Ninth Vongola Boss and his Dying Will Flames. Xanxus accused Tsuna of attempting to assassinate the Ninth and challenged him to the final match. During the "Sky Ring Battle" Xanxus managed to acquire all of the seven Vongola Rings; however, his blood was rejected as he was not the Ninth's real son but only an adopted child of the Ninth. This resulted in Tsuna winning the Vongola Rings, and title of the successor, to him and his guardians.
The battle against the Varia has come to an end, with Tsuna and his friends resume their daily life. Tsuna parts ways with Lancia and Basil, who are now returning back to Italy, where he is provided with Lancia's Boss Ring, and a jar of Dying Will Pills from Basil. The goodbye is interrupted by Lambo, who believes that the pills are candy and tries to take the pills are Tsuna, much to the annoyance of Reborn who shows no mercy towards punishing Lambo, who had only recently come home from the hospital after the Lightning Ring Battle. As usual, Lambo begins to cry and prepares to shoot himself with the Ten Year Bazooka, but is stopped by Reborn, who is shot with the bazooka by accident. Tsuna expects to see the older counterpart of Reborn but is shocked to find out that Reborn had completely disappeared, not replaced with a ten-year counterpart. Tsuna remains curious on why an older version of Reborn didn't show up and assumes that Reborn would return after five minutes pass, though is proved wrong as a day passed without Reborn returning. Tsuna explains predicament to Haru and Hayato, with Hayato speculating the possibility that Reborn may not exist ten years in the future. Tsuna returns back home, hoping that Lambo from ten years into the future would know what happened to Reborn, when he returns home, he requests Lambo to shoot himself with the Ten Year Bazooka, which Lambo declines to and claims that he never used the Ten Year Bazooka. Tsuna and Lambo argue over the Ten Year Bazooka, leading to Tsuna getting subsequently shot with it and sent ten years into the future.
Tsuna finds himself waking in a coffin, where he first encounters the twenty-four-year-old counterpart of Hayato Gokudera. The adult Hayato gives Tsuna instructions to kill a person named Shoichi Irie, in order to prevent the devastating future from happening, before Tsuna is given the chance to question why he's inside a coffin, the adult Hayato is quickly replaced by the fourteen-year-old counterpart that Tsuna is already well acquainted with. Tsuna explains to Hayato the information that he was previously given, and Hayato declares to kill Shoichi once they return back to the present, much to the discomfort of Tsuna who doesn't want to kill anyone. The two quickly realize that they've been in the future much longer than five minutes, and they should have already returned back to the present.
Much to their surprise, they do not return to the past after five minutes. Tsuna and Hayato soon come in contact with the future Vongola Famiglia, who are being slowly annihilated by a rival, the Millefiore Famiglia, and driven into hiding. It seems that the Future Tsuna ordered the destruction of the Vongola Rings, putting the Vongola at a huge disadvantage; most of the Famiglia's higher-ups and allies have already been eliminated.
Motivated by a desire to prevent this Future from coming about, as well as to return to the Past, Tsuna is advised by Reborn to gather the Guardians, starting with the strongest Guardian Kyoya Hibari. In the process, the Vongola battles numerous times with the Millefiore; while; fortunately, Tsuna learns how to use his Vongola Ring. His antics also alert the Millefiore to the presence of not only the existence of a young Tsuna being alive but the Vongola Ring's location. Events soon conspire that transfer most of Tsuna's friends and Famiglia to the future, making it imperative to return to the past; in order to accomplish this, Hayato reveals it is necessary to defeat Byakuran, the head of the Millefiore Famiglia, with the Vongola Rings. Thus, Tsuna and the Guardians, from the Past, undergo training to learn this Generation's unique style of fighting, using Boxes and Rings, in preparation for an attack on the Millefiore Base to be conducted in tandem with Vongola operations against the Millefiore worldwide.
Tsuna's training with Hibari drives him near death, forcing him to undergo the Vongola Trial of Succession. Tsuna's declaration of his resolve before the former Vongola Bosses yields the ability to combine the power of the Vongola Ring with his X-Gloves, producing the X-Gloves Version V.R. (Vongola Ring); while more powerful, the Gloves are unbalanced and difficult to handle; however, Tsuna is able to use the Gloves' increased to power to develop a new technique, the X-Burner, before the scheduled raid on the Millefiore Base. During this time, Tsuna receives a vision, along with Chrome, about a circular white machine with Shoichi Irie standing in front of that seems to have something to do with traveling back to the Past. Tsuna also begins to become more accustomed to the idea of leadership; however, the Millefiore discover the location of the Vongola Base and attempt to ambush them in the middle of the night, forcing the gang to attack earlier than expected. Tsuna and company infiltrate the Merone Base, which they discover is conveniently led by Shoichi Irie. Although the group dispatched several Millefiore thugs, Shoichi Irie soon plays his hand and manipulates the placement of the Base's rooms to separate the group.
Additionally, Tsuna is captured by a Millefiore technician, Spanner, after remaining behind as a decoy and defeating a force of Strau Moska robots. Surprisingly, Spanner does not kill him but offers to help Tsuna complete the X-Burner technique, on the grounds that he wishes to see it completed. Tsuna cooperates with Spanner after Reborn, who appears via hologram, urges him to; Spanner constructs Tsuna to use Contacts Lens to improve his X-Burner. Tsuna proceeds to use the X-Gloves to obliterate numerous Millefiore agents and obstacles, developing new Techniques, as he and Spanner, who is labeled a traitor, make their way to the control room to confront Shoichi Irie.
After receiving word of the Varia's victory in Italy, learning of the Real Six Funeral Wreaths and of the plot hatched between Future Tsuna, Future Hibari, and Future Irie, Tsuna asks Spanner and Irie to join the Vongola Famiglia and receives the Sky Vongola Box from the Future Irie. He begins training again in preparation for the Battle of Choice initiated by Byakuran; however, his Box Weapon attacks him when he first tries to open it.
To make matters worse, mid-training, Haru and Kyoko decide to stop doing household chores, as both become aware they are being left out of the loop; Tsuna ultimately reveals the entire situation to both of them, receiving advice from Kyoko that allows him to open his Vongola Box correctly.
After their training was complete, Tsuna and his Guardians proceed to the designated meeting place to begin the game of Choice. During the Choice battle, Tsuna engages and temporarily defeats the Millefiore Mist Funeral Wreath, Torikabuto; however, Tsuna was ultimately trapped within an Illusion.
During the Battle, he demonstrates not only his increased strength and the power of the Vongola Sky Box but again with his role as the Tenth, giving orders when the battle turns grim. However, he was too late to prevent Shoichi Irie from being attacked, and the Vongola lost the Choice Battle. Shoichi woke up to find out that they had lost. Tsuna didn't understand why it is so important to win even if it is for all of humanity. Shoichi then goes on to explain his past experiences and Byakuran's power.
Shoichi continues to explain that the reason Byakuran's so powerful is that he could take the best of the parallel worlds he exists in and use that knowledge to conquer each of them.
Another big surprise is that Shoichi used a special bullet to put Future Tsuna into a death-like state and that he knew the only help to defeat the Millefiore was that the Past Vongola Decimo and his Guardians defeat them. Tsuna finally understands why they are the only hope, but it is too late. Byakuran demands the Vongola Rings as they had lost, but Shoichi asks for a rematch as the last time they played Choice, Byakuran had lost, failed to pay and therefore had offered Shoichi any condition that he wanted next time they played. Byakuran denies this had ever happened and rejects the rematch as Boss of the Millefiore Famiglia; however, the Sky Arcobaleno Uni arrives, having been cured form an inflicted Drug which ‘erases’ emotions, and reveals that this bet had taken place. When Byakuran continues to deny this, Uni leaves the Millefiore and asks Tsuna to protect her, to which Tsuna said that he will protect her. The gang then runs away and heads back to the Vongola Base.
Tsuna and the others are ambushed by the Funeral Wreaths and escapes while Squalo is stalling Zakuro. They decided to hide at Kawahira shop under Haru's suggestion where they met Kawahira, the man whom Future I-Pin often mentioned when she's delivering his ordered ramen. Kawahira used his Hell Ring to fool Zakuro for a while, but not long after he left, Torikabuto, Kikyo, and Bluebell once again attacked them and nearly succeeded in capturing Uni if not for Gamma, Nosaru, and Tozaru's interference. Tsuna initially has difficulty in locating Torikabuto who is hiding in his illusion, but he quickly defeats him with Chrome's guidance. Succeeded in forcing Kikyo and Bluebell to retreat, Tsuna and the others continue their escape to a forest.
Later during the Battle between the Six Funeral Wreaths, Tsuna is waiting and guards Uni while everyone else is fighting. However, when he heard that the last and Lightning Funeral Wreath, Ghost, appears and suck out their flames, Tsuna decides to go and help. He counters Ghost's absorption with Zero Point Breakthrough: Revised, absorbing Ghost completely. Strangely, despite having absorbing Ghost, he didn't feel his flame power increased in any way. At this time, Byakuran showed up at the scene, revealing that all of the flames absorbed by Ghost has been transferred to him since Ghost is his parallel counterpart. With everybody exhausted from Ghost's absorption, Tsuna battles Byakuran alone. Tsuna seems to gain the upper hand, but Byakuran quickly overpowers him and nearly broke his neck, causing Tsuna to lose his consciousness.
Through Reborn's encouragement, Tsuna regains himself and tells Byakuran that he didn't regret everything that had happened to him and would give his life to protect everyone. Therefore, he vows that he will defeat him. Responding to Tsuna's will, Vongola Primo and his Guardians appeared from the Vongola Rings and then explained that the Vongola Rings aren't at their original form and that it had its highest Flame output restrained so that it can be safely passed down to their proper successors. However, seeing that Tsuna has inherited his will and believes that Tsuna will know the true purpose of the rings, Vongola Primo changes the Vongola Rings back to its true forms. With his newfound power, Tsuna easily overpowers Byakuran, forcing Byakuran to reveal his full power. As the battle goes on, Uni was preparing to sacrifice herself to revive the other Arcobaleno. Tsuna tried to convince Uni out of it but she had already decided since there's no other way. Eventually, Uni, along with Gamma, sacrificed their lives to revive the Arcobaleno, leaving Tsuna and the others grief-stricken of their death.
This enrages Byakuran who blames Tsuna for what happened, which Tsuna countered that it was Byakuran who made the world this way that caused Uni to sacrifice herself. Both of them then prepared to use all of their power, deciding to end the fight for good. Tsuna fires the X-Burner with full power, and after much struggling, finally incarcerated Byakuran without any trace. Despite the victory, Tsuna is depressed, wondering was their victory really worth the lives that have lost from the battle. The Arcobaleno then fully revived and assures Tsuna that with Uni's power over the Tri-ni-sette, all of Byakuran's actions will be negated and everyone who died will return, much to everyone's relief.
With the fight finally over, Tsuna and his friends give their farewells to their friends and Box Weapons of the future and return to the past. Tsuna, Lambo, I-Pin, and Reborn returns to their house where they are greeted by Nana and then are surprised to find Natsu, having been turned into a ring by the future Arcobaleno as a present, with him.
Back at the future, Future Tsuna awakes early from the round machine and returns to the surface ahead before his friends, looking at his coffin along with notebook left by his past self.
The Transfer Students
Before Tsuna and the rest went back to the present, an earthquake occurred. Because of this, 7 students from the Simon Middle School transferred to Namimori Middle School. They were Shitt P!, Kaoru Mizuno, Large Ooyama, Kouyou Aoba, Julie Kato, Adelheid Suzuki, and Enma Kozato. While Tsuna heads to school, Reborn receives a letter from the 9th Boss about Tsuna officially inheriting the Vongola Famiglia.
As the days go by, Tsuna, on his way home from school, sees Enma getting bullied; Reborn pushes him into the fight leading him to get beaten up as well. After this incident, the two begin to talk, and unexpectedly their rings begin to resonate with each other, and Enma runs away accidentally dropping his books in the process. Tsuna catches up with him, as he was trying to return the books, and in a display of both their clumsiness, they fell into the river. They then go to Tsuna's house to dry off.
This incident strengthens their newly started friendships, and they see that they had a lot in common. During the next few days, Tsuna finds out that Enma's group are actually members of the Simon Famiglia, and had come to attend Tsuna's Inheritance Ceremony. The two families start to bond with each other.
Meeting with the Ninth
As the day of the Ceremony draws nearer, Tsuna has a meeting with the 9th, who puts Tsuna under no pressure to accept his role, simply telling him that it was his choice. But the 9th did explain a little bit about the history of the Vongola and tells Tsuna to think about what he should do before making a decision.
Tsuna, who was confused as to what he should do, consults with Enma, who tells Tsuna about the abuse his Famiglia has received from others due to status. He also said that Tsuna was different from the other scary mafia people, and he feels he can be friends with him. After his conversation with Tsuna, he calls Adelheid to discuss Tsuna. Adelheid asks Enma to test Tsuna, to which Enma responds by writing a letter to Tsuna, telling him that he had been captured by the enemy and asking for help. However, Tsuna never got a chance to see this letter, as a wind blew the letter away, leaving Enma alone and betrayed in an abandoned factory yard.
Later, Tsuna visits the 9th once again, to give him his answer. Tsuna declines the role of the Vongola Boss, and as he was preparing to leave, gets an urgent call from Hayato telling him that Takeshi had been attacked, and was in critical condition at the hospital.
Reborn and Tsuna both hurry to the hospital, where the doctor informs them that even if Takeshi were to survive, he would most likely not walk again. However, they soon learn that after Takeshi was attacked, he had left a message written in his own blood, as a warning.
After asking the Simon to leave, Reborn explains that the word that Takeshi had written "Delitto", means "Sin", and goes on to explain a tradition of the Vongola, and the Vongola Sin. Reborn asks what Tsuna wanted to do, and Tsuna determined to catch the culprit, asks Reborn to tell the 9th to go ahead with the ceremony.
On the day of the ceremony, the culprits attacked the Ninth and managed to wound him, destroying the vial; however, it turned out to be a fake, and the real Sin was being held in a Dying Will safe that couldn't be destroyed by any weapon or Dying Will Flame; however, the Simon Famiglia managed to break it and take the sin, proving that they were the ones who attacked Takeshi and the Giegue Famiglia. Enma revealed that the Sin was originally the Simon's and that they transformed with its power. Tsuna then goes into Hyper Dying Will Mode to fight Enma. He then goes on to explain that the Sin belonged to the Simon Famiglia and that it was the blood of their first boss. Adelheid tells the story that during Vongola Primo's time, the Simon and Vongola Bosses were as close as brothers, but when the Vongola planned to take over Europe, they used the Simon as bait.
Timoteo says he never heard that story. Enma then asks Tsuna if he's ever heard the story since he is carrying the blood of Vongola, which Tsuna replies that he swears upon his grave that Vongola Primo is not a man who would do such a thing. This angers Simon and they make the declaration that Enma will inherit their Famiglia as the tenth boss and take revenge of the Vongola for pride and honor. Adelheid and the others then release their rings as Enma says that the reason that Vongola Primo got rid of Simon was because they had a power that rivaled the Seven Flames of the Sky, which is the Seven Flames of the Earth.
Alone, Enma defeated Tsuna's Guardians (excluding Lambo and Takeshi) and broke their Vongola Rings with ease, which enraged Tsuna, causing him to attack. He asked why he was doing this, which Enma replied that it was his own fault. He told Tsuna that the power of the Simon Famiglia is not yet complete and it is only at a seventh of it of its full power. Enma decided that he will leave for now since he only wanted to show the Vongola the living hell and immediately defeated Tsuna and broke his Vongola Ring.
After the chaos, Tsuna feels regret over what has happened; however, Talbot came and said there is still hope to repair the Vongola Rings stating that they can be upgraded with Tsuna's and the others Vongola Box Rings and the blood of Vongola Primo, "Penalty", to have immense power. If they fail, the Vongola Rings will lose their spirits and will never shine again. Talbot then asked Tsuna what will he do, and though Tsuna hesitates, he wanted to get Simon back for having done that to Takeshi and to save Chrome no matter what it takes. Tsuna becomes determined and agreed to upgrade the rings.
Outbreak of War
As Talbot was upgrading the Vongola Rings, Tsuna, Ryohei, Hayato, and Timoteo commented about how unbelievable the actions were of the Simon Famiglia. Tsuna still couldn’t believe that Vongola Primo was a traitor to the friendship and thinks that there must be a misunderstanding. When Talbot entered the room with "rocks," which were revealed to be the Vongola Rings, they thought that the upgrade had failed since the rings looked lifeless. However, Talbot told them that they must show their resolve to fully upgrade it. Thinking about Takeshi and Chrome's fate, they able to show their strong resolve and were able to upgrade the Vongola Rings. Tsuna's Sky Vongola Ring turned into the Ring of the Sky Version X.
After finding the location of the Simon Famiglia base on an unmapped island, the Ninth gives the task of subduing Simon to Tsuna and his guardians, with Reborn along as an observer.
Before leaving, Shoichi sends Tsuna a package, telling him how both he and Spanner got visions from past, and in the package are new contacts and headphones from Spanner. After arriving on the island and meeting the Simon Famiglia again, the Vindice intervene. They explained that the Simon and Vongola should never fight each other, but if they did, because of the oath between the founders, the losers would be locked in Vindice Prison forever. After agreeing to the fight, Enma explains that they will be ready for their goal in six days and leave. Tsuna activates his new X-Gloves and tries to give a chase but finds out they have vanished.
Ryohei vs. Koyo
After searching the island they eventually come upon Koyo Aoba, who fights Ryohei. After the battle, which ended up with a draw, the Vindice appeared and granted them a key that contains Giotto and Cozzato's memories of the past. Tsuna is saddened that Ryohei was taken, but Reborn reminds him that he should follow Ryohei words of protecting their pride.
Lambo vs. Large
Taking a rest, Lambo is led to an island surrounded by lava and Large, who is there, challenges Lambo to fight, while Tsuna, Hayato, and Reborn are helpless to stop it. When Lambo awakened his Vongola gear, Tsuna was amazed and glad that he was not completely defenseless. But when Large pushed Lambo into the lava, he was distressed but was relieved when he saw 15-year old Lambo. Tsuna gives into his guilt of making Lambo fight but was rebutted by 15-year old Lambo, saying that he was happy he was allowed to tag along with Tsuna and wished that Tsuna continue treating his younger self the same.
Hayato Gokudera vs. Shitt P!
They arrived in a town that is the exact replica of where Cozzato and Giotto first met and confronts Shitt P!. During her battle with Hayato, she revealed all of Tsuna's 'No-Good' aspects, much to Tsuna's dismay. However, Hayato just brushes it off and declared that he already knew all of them and still accept Tsuna the way he is because that is only a part of him. After Shitt P! was taken away after losing the battle with Hayato, Enma directly confronts Tsuna, challenging him into a fight. At this time, he revealed to Tsuna that Tsuna's father Iemitsu killed his family and sister, which shocked Tsuna greatly, enough to cause him losing his will to fight. Enma was about to deliver a finishing blow, but Enma's Earth Simon Ring went out of control and he was taken back to their base. Tsuna began to doubt and question his reason to fight.
Hibari vs. Adelheid
During Hibari's fight, Hibari gave Tsuna clues about pride is something that can never be given up and he slowly realized what his pride is. After witnessing the fourth key, they are confronted by Julie who revealed himself to be Demon Spade, the true ringleader of the war between Vongola and Simon. After witnessing the fifth key that shown the truth of the true extent of Giotto and Cozzato's friendship, Tsuna is determined to defeat Demon who has manipulated the Simon Famiglia from behind the scenes and to save Enma and Chrome, stating that he will never lose to his own heart anymore and believes that Iemitsu never killed Enma's family.
When he and the others arrive at Enma's throne inside the underground castle, he confronts Enma and tries to reason with him but to no avail, because Enma has been consumed by hatred and the desire to kill Tsuna for revenge. Tsuna decides to charge at Enma in one on one. Just as he is about to be sucked in by one of Enma's black holes, Tsuna commands Natsu to transform and managed to evade it. As the battle progresses, Tsuna's voice finally reaches Enma, who snapped out from the Simon Ring's control before remembering that Cozzato was never betrayed by Giotto. However, Enma is unable to control his own power and creates a huge black hole that will suck everything in, including himself. Tsuna refuses to run away and vows to save him, using XX Burner from his both hands and blasts it to the black hole, saving Enma.
Asking what Tsuna’s pride was, Tsuna explains that Hibari has given him a hint and he learns that pride is something that could never be given up. He confidently and sincerely answered that his pride is his comrades, his friends. In the middle of their reconciliation, the Vindice appears and decides that Enma was the loser and gave the Sixth key, a clear pacifier. Tsuna is surprised to see Reborn bothered by the clear pacifiers and wonders what the secret to it is. The Vindice tells them, that as the Simon Boss, Enma must watch the battle until the end and after the final Guardian's battle, he will be imprisoned. This makes Tsuna realize that the last Guardian battle would be Chrome against Demon Spade.
Tsuna and the others arrived when the fight is over; they're shocked to find that Mukuro has already defeated Demon. After Mukuro left Chrome's body, Tsuna saved her from falling flat onto the ground, only to be later shocked that Mukuro was now possessing Mukurou, due to him not being able to get to his body. Demon, after being “defeated,” took over Mukuro’s body while he was possessing Chrome. When the Vindice arrived, Tsuna and Enma made a deal with them, that if they defeat Demon, the Vindice will negate the war between the Simon and Vongola and free the guardians. Once the battle with Demon begins, Tsuna was saved from being captured into Demon Spade's illusionary space. He later witnessed the brief showdown between Demon and Hibari and was surprised to learn that Demon not only could utilize the six Rings of the Earth but also the Vongola Gears as well. After Hibari was also sent to the illusionary space, Tsuna went into Hyper Dying Will Mode and charged at Demon. However, he was quickly overwhelmed by a combination of the Storm and Lightning Vongola Gears until Enma joined the fight.
After learning that Demon was the true perpetrator behind the death of Enma's family, both Tsuna and Enma were determined to take him down. Without prior planning, the two bosses became the "Hyper Duo" and combined their attacks to damage Demon. When the smoke cleared, they were surprised to see Demon using another Vongola Gear to lessen the damage. When the battle took a turn for the worst, Tsuna was faced with the decision of sacrificing Enma to defeat Demon. While he was hesitating, Chrome stepped in and protected Enma, with the support of Mukuro, thus allowing Tsuna to fire XX Burner at its full potential. The attack drained Tsuna of every last ounce of his energy, but Demon managed to survive. The situation turned even more dangerous when Demon began his attack on the helpless Tsuna. Just as Demon was about to strike the finishing blow, the Simon Ring flew off and merged with the Vongola Ring.
After the union of the Vongola Ring and Simon Ring, the Seventh Key was shown to the all guardians and Demon. It contained the last piece of memory of Cozzato and Giotto which revealed the oath between the two bosses. After the vision, the Flame of Sky and Earth united to form the Flame of Oath. Tsuna used the special properties of the flame to repair his broken bones and enhanced them with a coat of Gravity. He proceeds to overwhelm Demon with the Flame of Oath and challenged Demon to a final showdown.
With the new power, Tsuna manages to easily overpower Demon and finish him off when the latter intended to run away using the attribute of Vindice. Demon refuses to die, and the two of them clashes until Demon leaves Mukuro's body and tries to escape through the portal. However, Bermuda interferes and dismisses the portal since it could only be entered by someone with a physical body. With the opportunity he has, Tsuna blasts X-Burner at Demon Spade's soul. As Demon Spade's soul slowly begins to fading away, the pocket watch that he always kept with him fell opened. Tsuna picks the pocket watch and sees the photograph of Vongola Primo and his Guardians with a woman cuddled close to Demon.
Demon, who's on the verge of death, says that the woman is his lover, Elena. He explains his introduction to Giotto by Elena and that they joined the Vongola. He revealed her own love for the Famiglia and his love for her and the Famiglia. This changed when Giotto disbanded the military forces to avoid fights, causing their base to be attacked and Elena killed. To fulfil her wishes, he swore to make her Vongola stronger. After his explanation, Tsuna questions the true meaning of Elena’s words, angering Demon who couldn’t believe he would understand her. Seeing that Demon would die soon and not wanting him to die while bearing hatred and regret, Tsuna lied that he understood her through Vongola Hyper Intuition and that she would feel gratitude towards Demon and thanked him for what he’s done. Hearing this, Demon begs for her forgiveness for not being her savior and warns Tsuna not to bring shame to the Famiglia that she loved. Afterwards, Tsuna knew Demon saw through his lie, which Reborn states that Demon lived to hear the same words that Tsuna told him from Elena. Tsuna and the others are overjoyed when everyone is freed and reunited, but they are interrupted by the Vindice, who tells to entrust them with the last key left by Giotto and Cozzato, showing that, to fool Demon, Simon lived away from the rest of the world. Cozzato, and Giotto, both believed that one day, they’ll be able to smile together; this being reflected through the tenth generation, Tsuna and Enma with their own Famiglias lives happily in peace.
Tsuna began to wonder the true nature of Arcobaleno and decided to ask Reborn directly about it. The next day, he and the others were surprised to found out that Chrome had been transferred to Namimori-Middle and surprised even more when she suddenly hugged Kyoko and cried. At the rooftop, it was then revealed that Mukuro had abandoned her. According to what Kyoko heard, when Chrome awoke in the morning she found a letter that tells her to get out and a Namimori-Middle uniform and Kokuyo Land empty. Tsuna questioned Mukuro's action, which Hayato concluded that Mukuro no longer needs her since he's already free, though, Tsuna doubts it.
At this time, Reborn arrived and told them that they had to accept Chrome in Namimori. Tsuna asked where he had been since morning. Reborn replied that Mukuro convened him to talk about Chrome and explained that Mukuro and his gang had gone to France to recruit Fran and meanwhile, he left Chrome in Namimori. Tsuna asked again why he only leaving Chrome but Reborn himself doesn't know but he had received her living expenses and for a meantime, Chrome will stay at Kyoko or Haru's place. After deciding they will throw out a party for Chrome, Tsuna asked Reborn about the Arcbaleno and Reborn said that it's about time that Tsuna knew everything. However, he added that he still wants to make sure Tsuna's growth by winning mimicry game at Chrome's party, making Tsuna thought that Reborn had fooled him again. He watched the mimicry game with the others and then felt sympathy for Chrome and wondered that if he knew Arcobaleno secret, he somehow felt that the everyday life that they had will be lost and might be better that he doesn't know anything. When it was Tsuna's turn to mimic, Tsuna tried his best to mimic Leon but Leon gave him 0 points as the result.
Later, Reborn requested Tsuna to do a favor for him, which Tsuna at first denied, thinking that Reborn would have him do something tedious. However, after Reborn explained his dream with the rest of the Arcobaleno and the curse of the Arcobaleno, Tsuna agreed alongside Dino, stating that teaming up with Dino made him feel reassured.
The next day, on his way to school, he along with Reborn, Hayato, and Takeshi were confronted by Kokuyo Junior High Gang, who declared war against Tsuna and Guardians as Mukuro stated that he would defeat Tsuna and destroy Vongola Famiglia. Tsuna refused this declaration, saying that he doesn't want to fight anymore. However, Mukuro revealed that he and his gang had become Verde's representatives for the upcoming Arcobaleno battle and thus, their fight cannot be avoided.
Tsuna and Reborn then head to Dino's hotel together, where Tsuna is subsequently taken to Xanxus's room in the hotel by Belphegor. As Xanxus makes threats to Tsuna and his team, Wonomichi arrives and announces the start of the Representative Battle of the Rainbow in four days.
1st Day of Representative Battle of the Rainbow
Later, as the first day of the Representative Battle of the Rainbow arrived, Tsuna was at first nervous, but then felt at ease when he noticed that his friends were acting normally and hoped that the day would continue that way. After school, however, the wristwatches announced the start of the Representative Battle, and during his way out of the classroom, he encountered Iemitsu, who prepared to battle him, stating to Tsuna that it was time he himself should treat him as an adult.
As the battle starts, Tsuna has various regrets about facing his dad; however, he quickly gets annoyed by his dad's responses to his worry and prepares to fight. Tsuna charges at Iemitsu, punching him, but Iemitsu appears unfazed. Tsuna punches even harder, this time activating his Cambio Forma Version X, but it still isn't enough. Iemitsu casually enters Hyper Dying Will Mode and tells Tsuna to watch carefully, as what he was about to do was a real punch; he then proceeds to punch Tsuna away through the ceiling. Tsuna, after landing, appears to be unconscious. Reborn, Tsuna, Dino, Hayato, Takeshi, and Ryohei gather around a table in Namimori Diner to discuss the results of day one of the Representative Battle of the Rainbow. Tsuna sadly recounts how his dad beat him with one punch but didn't destroy his boss watch. Reborn explains that he made a deal with Iemitsu- if Iemitsu didn't destroy Tsuna's watch, they would make an alliance with Colonnello's team. Suddenly, all of the boss, representative, and Arcobaleno watches start speaking. The speaker congratulates all of the participants and introduces himself as Checker Face. The watches then display the results of the first day's battle. Team Reborn concludes that they had to watch out for Team Verde. Hayato suggests that they skip school to not participate in the battle, but Reborn states that he didn't want their schooling to suffer from the battle. Dino also expresses his guilt that he didn't fight with them in the first battle, and that he should stay nearby their school. Reborn, however, just tells him and Romario, whom he called over, to search for two remaining representatives.
The group leaves Namimori Diner, and Tsuna is troubled, mentally commenting that he didn't want to return home to see his dad after such a devastating defeat to him. Takeshi, seeing his troubled state, invites him to go over to his house, as he had just bought a new baseball game. Hayato opts to go over to, just in case someone attacks Tsuna in the middle of the night, but expresses his excitement over Takeshi's sushi restaurant.
2nd Day of Representative Battle of the Rainbow
The next day at school, Tsuna expresses his shock at Enma's announcement that he and his fellow Simon Ring Holders had become part of Team Skull. As class starts, Dino walks in and introduces himself as their new English teacher. On the balcony, as they regroup, Reborn states that they had to go get some "valuable intel". They head to a mansion in the middle of a forest where Reborn states that one of their allied teams knew some information about Team Verde. When they arrive, Uni greets them cheerfully, opening the door. Inside, she serves them tea as Bluebell and Nosaru stick their tongues at them, Uni mentioning that she had got to know them really well and that she hung out with them a lot. Uni explains that Tazaru, Torikabuto, and Deisy all had their watches destroyed by Team Verde. Uni reveals upon Tsuna's question that her Arcobaleno Curse was a short life. Tsuna expresses his concern, but Uni tells them to fight for Reborn with all their strength, for two teams would be eliminated in the second day of the battle. Once more at Team Uni's rented mansion, Byakuran reveals that he had found a counter to Verde's machine, stating that they would fight genius with genius and machine with machine. Spanner and Shoichi Irie then show themselves and Byakuran recalls his future self's encounters with the two geniuses with a smile on his face. Spanner and Shoichi greet Tsuna. Suddenly, the wristwatch beeps and announces one minute until the battle starts.
All of Team Uni's members rush to their room, ready to fight, and Reborn notes that Team Verde was about to arrive. Byakuran answers Tsuna's question that he was Team Uni's boss representative and flies out into the sky with his wings, Tsuna following him by entering Hyper Dying Will Mode, propelling himself with Sky Flames from his X-Gloves. However, the wristwatch announces the battle this time to be 30 minutes long as it commences the battle. 24 minutes and 30 seconds of the battle remain. Tsuna and Byakuran are up in the sky keeping a lookout for enemies. Tsuna questions Byakuran why he, who killed thousands in both the future and parallel worlds, was fighting with all his heart for a single Arcobaleno. Byakuran simply explains to Tsuna that he was like him back then in the future, willing to fight for Uni. As they are talking, Team Verde attacks. Tsuna flies to Mukuro and attempts to stop him but much to Tsuna's frustration Mukuro taunts him which causes him to lash out fiercely, still feeling insecure after the tragic defeat from his father.
Meanwhile, Colonnello had released his curse and was planning to snipe Team Verde and Team Uni. As Mukuro and Tsuna continue to fight Colonnello fires his Maximum Rifle. Simultaneously, Ken, Byakuran, Mukuro, Chikusa, Fran, Gamma, and Kikyo are hit as Team Reborn's members watch in a mixture of shock, awe, and horror. Lal Mirch announces that Kikyo, Ken, and Chikusa had been eliminated, continuing to announce that although they were unable to confirm Gamma, Byakuran, Mukuro, and Fran's watches' destruction, they had all suffered injuries from trying to protect their watches. Iemitsu contacts Tsuna through his X-Headphones to check if he was alright. Iemitsu tells Tsuna to get as far away from the battle as possible, as Colonnello was going to fire a shot that would eliminate Byakuran and Mukuro Rokudo, eliminating Team Uni and Team Verde. Tsuna refuses to allow them to hit Byakuran, so Iemitsu announces that the alliance between them had been officially terminated and that Colonnello would be firing at them as well in the next shot.
Iemitsu tells him that if they were going to stop them from eliminating Byakuran, then he had to re-assess their alliance, telling Tsuna to quickly make his decision, as he wouldn't wait much longer. Iemitsu asks Tsuna on the course of action, and Tsuna tells Iemitsu to shoot. Tsuna then activates Mitena di Vongola Primo and tells his teammates to prepare for the second shot. Iemitsu tells Colonnello to shoot. Lal Mirch isn't sure about the shot, but Iemitsu tells him that his un-cursed time couldn't go to waste, and to shoot. Colonnello fires Maximum Rifle. Tsuna charges and so does Gamma. Uni cries out in anguish but Reborn rushes to stop the attack. As Tsuna, Gamma, and Reborn are all about to be hit, Byakuran intervenes, stating that they couldn't lose. Tsuna asks why, and Byakuran reveals that despite his dreams in the future, he was only awaiting death. He mentions how Uni became the warmth of his life and states that this time, he would be the one to protect her heart. Byakuran then tells Tsuna to charge and defeat his father. Byakuran falls to the ground, heavily wounded and his Rainbow Wristwatch destroyed, signifying Team Uni's defeat. Tsuna rushes towards Iemitsu to avenge Byakuran, saying he will never forgive Iemitsu. Iemitsu tells Colonnello to leave this to him and to save his un-cursed time, and Colonnello states, "Present, stop" and wishes Iemitsu luck. Tsuna punches Iemitsu into the ground, but the latter kicks the former, sending him hurtling back. Iemitsu comments to Tsuna that he hadn't improved at all, but Tsuna, enraged, tells him to shut up and slams him into the ground again.
However, Iemitsu appears to be unfazed and slams Tsuna into the ground next to him. Tsuna wonders, in his pain, why he still couldn't beat Iemitsu. Tsuna recalls how Iemitsu left him and Nana in their house all alone, how he does when he returned, would only sleep or talk about meaningless things. Iemitsu, now sitting beside Tsuna, apathetically states that it was boring fighting with him. Tsuna exits Hyper Dying Will Mode and bursts out at Iemitsu if he was insulting him. Lal Mirch notes that since Tsuna's has exited Hyper Dying Will Mode, his willpower and energy had collapsed. Iemitsu, meanwhile, doesn't respond and Tsuna repeats the question furiously, but Iemitsu still doesn't respond and tells Tsuna to take off his boss watch so that he could destroy it. Tsuna refuses, so Iemitsu lifts a boulder and hurls it at Tsuna. Colonnello and Lal Mirch shout out that it was going to crush Tsuna. However, Tsuna is saved by Reborn in the nick of time, who was in his curse-released time. Reborn shoots the boulder and destroys it into letters, spelling out the word "C-H-A-O-S" and they land around Tsuna. Iemitsu appears to be shocked, and Lal Mirch and Colonnello chorus in unison that there was only one person who could pull off a feat like that. Reborn, in his curse-released form, stands before them, with his hat shading his eyes. Tsuna asks Reborn who he is, not recognizing him in his adult form. Reborn looks at Tsuna with a hard expression and tells him that it was lesson time. Reborn easily heavily injures Iemitsu while in his un-cursed form, Tsuna being oblivious to the adult Reborn's identity. Reborn tells Tsuna two weaknesses of his for when he has to fight Iemitsu again. When Reborn runs out of his un-cursed form time, Tsuna is still oblivious to Reborn's identity when Reborn changes into his cursed form right behind a boulder. Reborn reminds Tsuna of his un-cursed form's lesson, which Tsuna takes into mind, and fights Iemitsu. Tsuna's skill and speed have suddenly improved, which Iemitsu notes, and Reborn mentally tells Tsuna to show him what his student was capable of.
Tsuna uses Zero Point Breakthrough: Revised and absorbs Iemitsu's Dying Will Flames. Colonnello and Lal Mirch note that Tsuna's Flame combustion power was increasing. Tsuna finishes absorbing the Flames of Iemitsu's attack and pushes himself back, then propels himself with his X-Gloves towards Iemitsu once more. Tsuna and Iemitsu trade blows, but ultimately Iemitsu grabs hold of Tsuna's leg. Tsuna quickly reacts and thrusts his hand towards Iemitsu's face and uses X-Burner at point-blank range, much to Iemitsu's surprise, though he manages to escape. Suddenly, their Rainbow Wristwatches beep out and announce the end of the second day's battle. Tsuna and Iemitsu stop their battle and Iemitsu compliments Tsuna, stating that he was sincerely trying to break his boss watch at the end. Iemitsu comments that the battle was fun, angering Tsuna, who scolds him for taking the battle un-seriously. Iemitsu once again comments that Tsuna sounded just like Nana. Tsuna, despite that, tells him that he would win next time, Iemitsu responding with an "OK." Tsuna once again wonders who the man in the suit was, when suddenly Hayato and Takeshi arrived, having arrived here by bike by propelling themselves with Hayato's bombs.
Hayato and Takeshi congratulate Tsuna on his tie with Iemitsu. Tsuna says modestly that it was all thanks to the mysterious man in the suit, which Reborn reacts with a glint in his eye. As Iemitsu asks Lal Mirch on the other teams' situation, Basil's voice comes through her headphones, frantically saying that things were bad and to connect him with Iemitsu immediately. Basil had been spying on Team Skull when a large group of Vindice led by the Vindice Arcobaleno had attacked all of the members of Team Skull, leaving them mortally wounded. Skull had been attacked and wristwatch stolen and changed to Bermuda von Veckenschtein. Team Reborn is informed of the unfolding events until suddenly Checker Face announces the accumulated results for the second day. Tsuna and his representatives rush to Namimori Hospital to see if the Simon were alright when they meet an upset Basil who reassures them that they would make a full recovery. Suddenly, Kyoko arrives and states worriedly to Tsuna that Chrome Dokuro was unwell and her internal organs were gone. She tells him that Chrome had been calling out for "Boss." Tsuna rushes to Chrome along with Kyoko. Tsuna apologizes for not noticing her condition earlier but is cut off by Chrome who requests to join as a representative for Team Reborn. Tsuna firmly refuses for her well being.
Later in Takeshi's dad's sushi shop, Hayato and Takeshi commend Tsuna on his decision, stating that Reborn would have done the same. Hayato wonders where Reborn was, to which Tsuna answers that he was apparently meeting with the other Arcobaleno to discuss Bermuda. Suddenly, however, everyone notices an ominous Flame. As Reborn returns from the meeting, he finds Tsuna, Hayato, and Takeshi battling a Vindice member. As soon as Reborn reaches them, the Vindice vanishes. Afterward, Team Reborn's members discuss the day's events, and Reborn triumphantly states that he had found a new representative.
3rd Day of Representative Battle of the Rainbow
At exactly 12 A.M., the watches signal the start of the third day of battle. Tsuna expresses his shock that the third day was starting so soon. They quickly get changed and run to the playground to avoid involving the locals getting involved. Team Reborn runs into Mukuro Rokudo and the rest of their team.
Reborn questions his presence, but Mukuro dismisses the question and comments that the situation was fortunate, as he didn't need to waste time finding them. The Rainbow Wristwatches announces the start of the third day of battle, the time limit is 12 minutes. Ken confidently announces that he and Chikusa had spare watches. As with the other battlefields, 3 Vindices arrives on the battlefield. The Vindice suddenly attack Mukuro and Tsuna with their chains, creating an enormous explosion. Each team's representatives call out to their bosses, worrying about them. As the explosion's smoke cloud clears, Mukuro and Tsuna agree to temporarily team up, with their strongest weapons at the ready.
With Fran sleeping, Mukuro Rokudo and the rest of his gang decided to team up with Tsunayoshi Sawada and his team to defeat the three Vindice members. Hayato unleashed his Sistema C.A.I. to shield them from the attack of the Vindice. The group members work together using combined attacks. Tsuna uses Hyper X-Stream as Mukuro summons corpse eating crows to devour the Vindice. After the explosion destroys Vindice's hats and coats, they reveal their faces. Everyone was shocked to see Pacifiers hung on their necks.
Mukuro and Tsuna comment on the zombie-like appearance of the Vindice, who proceed to praise them for their valiant effort and attack them again, refusing to reveal any information. Tsuna fires with X-Cannon to distract so Mukuro able to finish them off. Mukuro is unable to do the combo move of Genjū Gagaia, as Fran is still asleep and the Vindice easily deflects his attack. Realizing that they were overwhelmed, both teams started to lose hope. At this time, however, Chrome appears as Reborn's representative and offered to support Mukuro's illusion to help them.
Tsuna expresses his surprise as she is still without organs but had still managed to arrive to fight. Verde equips Flan's equipment onto Chrome to do the combo move in Fran's place. Tsuna grabs Mukuro by the shirt and demands why he had not supported Chrome with his illusionary organs. However, Reborn revealed that Chrome had been the one refusing Mukuro's illusions. After they stopped sharing one body, Chrome began to change and expressed her desire to be seen as an individual, and not just Mukuro's replacement. She makes her resolve to protect everyone she loves and generates a powerful Mist Flame, recreating her illusionary organs in the process. With her energy regained and her resolve found, Chrome combines her strongest illusion with Mukuro's and creates Genjū Mugaia.
Mysteries of the Arcobaleno
With the majority of the Vindice defeated, Tsuna proceeds to fight the remaining Vindice. Reborn realizes he is protecting the boss watch and yells at him not to care about it and to fight with his dying will. Tsuna successfully defeats the Vindice and Reborn reveals his true motive for entering the Representative Battle, which was because of Tsuna's bad grades. Suddenly Bermuda requests to speak with Reborn and sucks him into a black hole, and Tsuna flies after him only to be sucked in too.
They land into a cave, which had ominous carvings of the Arcobaleno cycle. The engravings on the cave walls tell the story of how the strongest people of the era are taken to a mountain and turned into Arcobaleno, doomed to protect the pacifiers until they cannot be used anymore and a new cycle of the strongest people begins. Jaeger and Bermuda arrive and further explain that the Vindice were in fact what became of Arcobaleno- if they survived the removal of the Pacifiers. Bermuda also reveals that the curse wouldn't be removed; it was just a farce to gather the seven strongest people. Bermuda asks Reborn to assist him to destroy the Arcobaleno system by killing Checkerface, but in the process, all the Arcobaleno will die. Suddenly Tsuna cuts in and yells that he would not accept it and he will find another way, which leads to a brief skirmish between the two parties.
Tsuna is losing, which causes Reborn to yell in panic. Bermuda uses this fight as an example and says that whether or not they assist him, they were all going to burn in hell no matter what is done and they exit. Reborn tells Tsuna in defeat that it was clear that he could not beat Jaeger in the first place, and he tells Tsuna to give up on him and the Arcobaleno. Tsuna expresses his dismay over Reborn's odd statement, shouting that it was weird that Reborn said he couldn't win as Reborn was the one who was always telling him he could. Reborn replies that those times he knew tsuna could win, but this time he can't. They leave the cave and Tsuna runs home in anger and despair, and decides to take initiative despite Reborn admitting defeat.
Tsuna arrives home and finds about Iemitsu's injuries, and then attempts to sleep but cannot. He goes down to the kitchen and sees Lambo, trying to mix Basil's strawberry juice with his grape juice. Lambo proceeds to fill up the missing part of Basil's drink with his grape and claims it was perfect. Tsuna suddenly realizes by 'filling up the missing part' he could solve it. He quickly calls the 9th to ask for someone's address and enters hyper dying will mode. He goes to all the Representative Bosses homes and requests each of them to lend him their strength.
The next morning, Tsuna falls asleep against a wall. He is awakened by Kyoko, who greets him and asks for his good luck charm, as she wanted to add more prayers to it with Haru. When Chrome appears and leaves with Kyoko, Tsuna thinks of the conversation he had with Talbot the night before and their discussion on saving the Arcobaleno. Lambo had given Tsuna the idea of replacing an Arcobaleno's removed Flame with another Flame of the same type. Reborn interrupts Tsuna's thoughts and Tsuna takes him to Namimori Shrine. Reborn provokes Tsuna, causing him to go off on Reborn about giving up hope of living. After Tsuna finishes his rant, he exhaustedly sits down on a step and says that he will not let Reborn die. As he said this, however, Tsuna found Reborn fell asleep. He tried to wake him up but quickly changed his mind when remembering what he will do if he forcefully woke him up, leaving him no choice but to return home alone. Unbeknownst to him, Reborn just pretended to be asleep and was proud of his student even though he said that it is still impossible to prevent him from dying.Tsuna visits Hayato and Takeshi at hospital, saying that he has something to discuss with them and he had told Xanxus, Mukuro, Byakuran, and Enma yesterday, much to Hayato's dismay since he's a day late even though he's his right-hand man. Tsuna quickly apologizes and explains that since he had been dependant on his Guardians and Dino, he felt that they will help him anyway as he considers them as his family, apologizing that he should've told them first since they're friends, to which Hayato and Takeshi reply that they are family and there's no need for him to be formal. Tsuna thanks them and begins to explain everything he has heard yesterday from Bermuda along with his plan. After explaining everything to them, Tsuna goes to Dino and Hibari at Namimori Mountain and was shocked to find out that they've been fighting ever since the last battle with Mammon. They stopped, however, when Tsuna reveals how urgent the situation he's going to explain and they are shocked to know what will happen to Reborn and how powerful Team Bermuda is. After school, Tsuna gathered all people he has visited in his house and request for all of them to fight together, explaining everything about the Vindice, Checker Face, and information that Talbot has provided him as they arranging plans to defeat Team Bermuda.
4th Day of Representative Battle of the Rainbow
Tsuna, along with Enma and Basil became the Commanding unit of the entire Allied Team. Tsuna decided to defeat the Vindice one by one, starting from Alejandro who comes alone while the other remaining squads prevent Jaeger, Big Pino, and Small Gia from leaving their places. The three of them encounters Alejandro and briefly fought Alejandro's dolls, Ginger Bread. With the three's teamwork, they able to easily defeat Ginger Bread and destroyed Alejandro's wristwatch, disqualifying him from the battle.
They immediately went to where Small Gia and Big Pino are, who were being occupied by Hayato, Takeshi, Chrome, and Fran. They arrived just in time to save the four right before Big Pino's attack hit them, fighting them in their place. While Tsuna and Enma managed to defend themselves from Small Gia's attacks, Basil, however, was defeated by Big Pino's attack. In anger, Tsuna attacks Small Gia, but the latter uses one of his weapons to make a flash that momentarily blinding Tsuna's vision. Small Gia was about to deliver a blow at Tsuna, but Takeshi quickly seizes him from behind with Hayato's dynamites in hand and Hayato distracts Big Pino until he's close enough to reach his battler watch. With Enma's gravity manipulation that stopping the two's movements and with Chrome's and Fran's illusions, they were able to destroy Small Gia's and Big Pino's wrist watches without harming both Hayato and Takeshi.
After recovering from the last battle, Tsuna and the rest of the remaining members confront Jaeger and Bermuda, saving Hibari who was about to be hit by Jaeger's attack. Tsuna starts to attack Jaeger continuously and surprised by the fact that Jaeger didn't short warp to dodge his attack. Noticing that Jaeger's breathing is unstable like Small Gia did, he came to the realization that the Vindice are unable to survive on their own without Bermuda supplying them with his flames. Jaeger attacks Tsuna again but stopped by Fran, Chrome, and Enma, who is then quickly defeated by Jaeger. After finished replenishing enough flames for Jaeger, Jaeger attacks again from behind Tsuna, but this time was blocked by Mukuro and Hibari. Jaeger short warped and stabs through Hibari's and Mukuro's shoulders. However, this gave Mukuro opportunity to freeze Jaeger's arms, preventing him from escape. Using Enma's Simon Ring, Tsuna defeats Jaeger by using X Burner that converted with the Earth Flame's gravity. Before Tsuna could destroy Jaeger's boss watch, however, Bermuda interferes, entering battle by releasing his curse.
With Bermuda able to short warp within infinite times, Tsuna was cornered as he is unable to read his movements. Reborn entered the battle, releasing his curse. At first, he is able to dodge Bermuda's attacks, but soon was cornered and the attacks finally hit no matter how fast Reborn tried to dodge it. Finally using his gun, he shot a bullet that Bermuda easily dodged. However, it turns out that bullet was actually not aimed for Bermuda, but for Tsuna. The bullet changed direction and shot into Tsuna's forehead. Knowing it was a Dying Will Bullet and that Tsuna is still alive, Bermuda was about to kill Tsuna, but a hand appeared from his stomach and stopped Bermuda's attack. Another Tsuna emerged from the fallen body and declared he will defeat Bermuda with his Dying Will, removing his X-Gloves and Vongola Ring, much to the shock of both sides as Tsuna entered the last stage of Dying Will Mode, Ultimate Dying Will Mode. With the newfound power and confidence, Tsuna able to stop and counter all of Bermuda's attacks. Having no choice, Bermuda used his most powerful technique, but Tsuna able to see it through and defeats him and destroyed Jaeger's boss watch.
Wonomichi declared Team Reborn as the winner. Tsuna told Wonomichi that they already knew the secret behind the Arcobaleno and the true purpose of the Representative Battle of the Rainbow, much to Wonomichi obliviousness. At this time, Checker Face reveals himself directly to them. As Tsuna reveals his intention to negotiate with the latter, Bermuda warns him that Checker Face will take them to the dimension where he exists to curse them. Hearing this, Checker Face explains that he is real and merely hid his aura using Segno Ring. Removing his mask, he revealed his true identity as Kawahira.
The Truth of Tri-ni-sette
Kawahira reveals that he and Uni belong to a special race that had born and lived even far before humans with their duty is to protect the Earth. However, over the times, their race slowly dies, leaving only him and Sepira to maintain the Tri-ni-sette. Unable to maintain them with their powers alone, they split the Tri-ni-sette into the set of Vongola Rings, Arcobaleno Pacifiers, and Mare Rings. Kawahira then demands them to return the Arcobaleno Pacifiers to him. Tsuna interrupts, thinking there has to be another way to maintain the Tri-ni-sette, something that Kawahira doubts and warned him that he is the first one on the list, which Tsuna replies that he already prepared. Talbot arrives, proposing to protect the Tri-ni-sette with the special jars that he made that no longer require Arcobaleno. Finally found a way to entrust the Tri-ni-sette to the future generations, Kawahira removes the Arcobaleno curse and leaves the Tri-ni-sette in Bermuda and the Vindice's hands to protect.
Shortly after, Tsuna visits Basil and Dino in the hospital with Reborn and was shocked to find Varia, Byakuran, Hibari, and Kokuyo Gang also submitted into the hospital, which causes a fight and part of the hospital destroyed. At the rooftop, Reborn thanked Tsuna that his efforts allowed him to live longer, much to Tsuna's embarrassment. Tsuna then reminded about the man in a suit who has helped him fighting against Bermuda, asking who was he. Reborn questioned whether Tsuna still hasn't realized yet who he was.
Tsuna receives an invitation to Collonnelo and Lal's wedding with Collonnelo indirectly told him to get a girlfriend soon. Reborn quickly appointed Bianchi as Tsuna's love tutor and make him choose between Kyoko and Haru. Thinking that Kyoko might respond differently this time, Reborn shot Tsuna with Dying Will Bullet, making the latter enters Dying Will Mode and declares he will confess to Kyoko, looking for her everywhere in Namimori. When he found her and was about to confess, however, he was interrupted when Haru in danger and saved her as his Dying Will Mode runs out. Kyoko then tells Tsuna that he's extraordinary, which made him happy. However, he realized that nothing has progressed between him and Kyoko. Reborn cuts him off, revealing that he needs to decide whether he will become the Vongola Decimo or not, which depends whether he will leave him or not. Tsuna immediately states he doesn't want to become a Mafia boss. Hearing this answer, Reborn leaves, saying that he no longer has any business with him.
A week after Reborn's departure, Tsuna realized that he still lives his 'No-Good' life, frustrating him. He is soon shocked by Reborn's return who declares he will make him the Neo Vongola Primo, which similar as being Vongola Decimo and already has the ninth's permission and has invited his friends to celebrate his tutelage. Reborn reveals that even though it's not much, something did change from before, making Tsuna realized that unlike before, he now has friends that he could rely on when necessary. He then asks about the pacifier hanging around Reborn's neck. Reborn explains that he cannot let go of it and made a replica, making Tsuna laughs and comments he is indeed a baby, angering Reborn. As they go to where his friends are, Tsuna thinks how his life has changed completely to better, and all thanks to the arrival of his tutor and partner, Home Tutor Hitman, Reborn.