Shoichi Irie asks Yamamoto if he can see anyone from his current position, the latter responding in the negative. Shoichi is so sure that the enemy is concealing themselves with Illusions, so he lowers the decoy so Yamamoto can reach with his sword. Yamamoto senses something, jumps off his bike, and charges toward the decoys, when one that is hit by an unknown weapon explodes into a pillar of thick vines. Yamamoto is caught unawares and is quickly ensnared by these vines, which knocks Shigure Kintoki out of his reach and pins him to the ground. Saru appears. After making a comment that strikes Yamamoto strangely, an Illusion melts away to reveal that Saru is actually Genkishi in disguise, already fully decked out in his armor.
As Genkishi strikes a seemingly final blow, Yamamoto activates his Rain Vongola Box and summons his Vongola Rain Akita to the battlefield, with the Akita wielding one sword made of Rain Flames and Yamamoto wielding two others just the same. Yamamoto says that his name is Jirou, and that he holds onto his three short Blades for him. Yamamoto also comments that he and Genkishi are the same in that they both use four Swords. He proceeds to ask Genkishi if he could get his fourth one, Shigure Kintoki, which was knocked away. Genkishi shoots invisible Sea Slugs at Yamamoto, who calmly dodges by shooting a powerful burst of Rain Flames to both get away from the attack, and propel him towards his fourth Sword, which he grabs. Using his other short Blade, he shoots another burst of Rain Flames at the ground to put some distance between him and Genkishi, and finally releases a third burst to charge his opponent.
Genkishi vanishes after their Blades connect, and in a swirl of vines, attempts to hit Yamamoto with more invisible Spectral Sea Slugs. Yamamoto again dodges with a burst of Rain Flames. Reborn comments that not only can he now fight aerially, but he can also use his Rain Flames to detect where the invisible attacks are coming from. In an instant, Yamamoto throws two short Blades at Genkishi. When Genkishi says that he shouldn't be able to see through his Illusions, Yamamoto reveals that he had his Rondine di Pioggia ver. Vongola above casting down Rain Flames, utilizing the Rain's tranquility to slow down his Slugs, and wherever the movements were off, that was where Genkishi was. The Rain Swallow's name is Kojirou.
Squalo explains to Dino and Reborn that the reason Yamamoto was doing so much better is because for the time being, he's completely devoted to the Blade instead of baseball. Mainly because in his last battle with Genkishi, he thought he could win, but was utterly beaten. Yamamoto felt he shamed the blade and didn't do everything he could to grow stronger. So without that weighing him down, he's been able to train more effectively.
Reborn comments that Yamamoto shares that decision with the First Rain Guardian, who threw away his passion for music to help his friend, the Vongola Primo. They even share the same Weapons, three short Blades and one long Katana. Yamamoto commands Kojirou to Cambio Forma (Change Form). Kojirou fuses with the Shigure Kintoki to form the Asari Ugetsu's Four Irregular Swords. Genkishi says he won't hold back and activates his Hell Ring to utilize his Phantom Knight form. Consequently, he begins going on a rant about how he is worthiest of the title of Mist Guardian, to protect Byakuran, whom he refers to as "God". Shoichi says that the Hell Ring is driving him mad, and Byakuran comments to Bluebell that he likes Genkishi because "It's so easy to take a simple mind in the palm of his hand". Back at the battle, Genkishi states that he lost to Tsuna because his eyes were driving him insane, and they stopped him from using even half of his power. Reborn agrees with that, citing errors in Genkishi's movements back then. Yamamoto, however, is not fazed.
Genkishi launches a double attack of his Blade and Spettro Nudibranchi, becoming the move Danza Spettro Spada. Yamamoto counters with Shigure Soen Ryu: 4th Form: Gofuu Juuu(May Wind; October Rain), causing Yamamoto to evade the moves at a speed so incredible which made Yamamoto impossible to be attacked.
Using the Mist's Construction, Genkishi makes 9 more copies of himself and repeats the move, this variation being called Extra Danza Spettro Spada, which are so numerous that Ryohei says it's like a solid mass of Flame. Yamamoto counters with his Shigure Soen Ryu: Aggregate Art: Jiunoka.
Genkishi]pulls all his copies back into himself in order to regain his full power, only to see Yamamoto charging straight at him by using his three short Blades to propel himself. Genkishi realizes that Yamamoto isn't moving faster - he was moving slower. He discovers Rain Flames on himself, and sees that he's been hit. Yamamoto wins the fight with his Shigure Soen Ryu: 8th Form: Shinotsuku Ame.
Afterwards, Genkishi lies defeated. Kikyo comes by and activates his previously planted Bellflowers on Genkishi, the former telling the latter that it was by the order of Byakuran. Genkishi refuses to believe this and, until the Bellflowers kill him, believes that Byakuran would save him.