Fran is a Frenchman and lived with his grandmother in the Jura region before joining the Varia. Introduced during the Varia attack on a Millefiore Famiglia base in Italy, Fran is Mammon's replacement as the group's illusionist.
Due to his Hell Ring, it is most likely he has somehow suffered 666 events throughout his life as he is able to use his Hell Ring which can only be used by suffering 666 events.
Merone Base Invasion Edit
Fran participated in the invasion and subsequent defense of a Millefiore Base in Italy in the same time frame as the Merone Base Invasion by Tsuna, his Guardians, and Lal Mirch. Fran was paired with Belphegor and ordered to explore the surrounding area to the base and fight any Millefiore soldiers they found. After Belphegor dispatched a number of Millefiore soldiers (and a large section of forest), they came across Olgert, and very much to their surprise, Bel's supposedly dead twin brother - Rasiel. When it came time to fight, Fran couldn't open his Box due to the fact that he needs to do a hero-like pose before opening his Box. He couldn't do his usual pose because it involves reaching over his head, which he couldn't reach because of the frog hat. After Rasiel incapacitated Bel, Fran was able to create an illusion and escaped, not only to save their lives but to also witness Xanxus fighting with Rasiel.
According to Lussuria, Fran went to visit a girl whose name was W.W after the Millefiore Castle Invasion. The romanized translation of what Lussuria said was "Daburyu," which is the letter W. It is later revealed that Fran went to Vindice Prison to help Mukuro escape prison by posing as a member of the Millefiore Famiglia. The Milliefore Familgia were about to release Ghost only to find that someone had posed as a member from their Famiglia and released Mukuro Rokudo. Fran is later seen at a hideout with the girl that was revealed to be M.M., who was there with Ken Joshima and Chikusa Kakimoto. M.M. scolds Fran for putting her bag upside-down and for sneezing on her expensive coat. Fran complains that he always gets scolded for everything, even though he was the one who had helped Mukuro escape. Chikusa says that Mukuro will need some time to recover, since he had been floating in a tank of water for ten years. Later on, in the final battle between the Vongola and Millefiore Famiglia, Kikyo, Zakuro, and Bluebell, who have seemingly killed the entire Vongola Famiglia, are attacked by illusions created by Mukuro.
Fran, who reappeared beside Mukuro, complained that Mukuro had taken the "spotlight" again and that the people that they believed to have killed were really an Illusion, and that the Real Funeral Wreaths had in fact killed no one. Belphegor, who felt a bit annoyed by how the illusion worked out, complained whether they really had to die in the illusion. Fran responded that illusions had to be "realistic" and that "illusions were somewhat like pranks." Mukuro said that he was wrong and comically stabbed Fran in the head, which shocked Lussuria and Ryohei. Mukuro said that the real reason was to find data on the Six Funeral Wreaths, and to serve as a warm up. Bel, who still believes that the illusion was still ongoing, asked how long the illusion would last. Fran reassures everyone that "pineapple hair wasn't an illusion" and that he helped him escape from Vindice Prison. Kikyo applauded Mukuro's apprentice for hoodwinking the Vindice, and Fran told Mukuro that he was a celebrity now, but Mukuro once again stabs him in the head to silence him. Fran then told everyone that the "rehearsal was over" since the Funeral Wreaths that have fully healed from the attack earlier are ready to wipe them out again. Fran tells Mukuro he should sit down because he just got his strength back or wait until his Vongola Box got there. Just when the two sides have begun to fight again, out of nowhere, Ghost arrives on the battlefield.
Ghost then started to drain Fran's Dying Will Flames along with everyone else that is present. The Varia started to attack Ghost, but to only find out that it had no use. After the battle, the rest of the Varia head back to Italy.
The Varia decide to recruit Fran as a new Varia officer. In the present, he lives in an unexplored region countryside of France called "Jura" with his grandmother. Viper asks Fran's grandmother where he was, to which she answers that he's playing upstream in the river at the west side of the countryside. They see him later on a river alongside with the Kokuyo Junior High Gang, excluding Chrome Dokuro, who are also looking for the boy. This time, Fran wears a giant apple head instead of a frog head, the Varia spotting him as the present Fran commented that his grandmother's bentos were awful as usual.
When he noticed Mukuro and the others' present, he mistakes them as "fairies," and does an exorcism dance, calling Mukuro, "pineapple head fairy" and Varia, "tooth decaying fungus," much to their annoyance. Fran starts to running away from them when Belphegor throws knives at him, which do not affect him as he blocks them with his hat, revealing it to be an illusion. He is chased after by Ken and Levi, who try to coax and intimidate him into calming down, respectively. Mukuro and Squalo stop him and find that he has lost his memories from the future because his head was hit by a cheese block, according to his grandmother. Mukuro and Squalo argue that neither of them needs Fran. The group negotiate and are about to decide with a game of ladder which side must take care of Fran when he interrupts and decides which group he will go with.
1st Day of Representative Battle of the Rainbow Edit
In the end of the first battle, it is shown that Fran has joined Mukuro and is part of Team Verde. He is proudly referred to by Verde, along with Mukuro, as the Illusionist Duo.
2nd Day of Representative Battle of the Rainbow Edit
On the second day of the Representative Battle, Fran is seen firing missiles from Verde's Reality Illusion Gloves. When Colonnello fires his Maximum Rifle, Fran is injured protecting his Rainbow Wristwatch. Mukuro sees Fran's bad condition and chooses to retreat, taking Fran with him. Shortly, however, they were attacked by a Vindice and nearly overpowered by him, but Fran was able to use his illusion to trick the Vindice, saving himself and Mukuro.
Third Day of Representative Battle of the Rainbow Edit
On the third day of the Representative Battle, he was supposed to assist Mukuro, Ken, and Chikusa to defeat the Vindice, but fell asleep, forcing Team Verde to form a temporary alliance with Team Reborn. When both of them started to get overpowered by the Vindice, Mukuro ordered M.M to wake Fran up, but he was too terrified by the Vindice's appearances whom he mistook as death gods and fainted again.
Fourth Day of Representative Battle of the Rainbow Edit
On the fourth day of the Representative Battle, he was chosen as one of representatives who will fight Team Bermuda. He, along with Chrome, Gokudera, and Yamamoto, fought Small Gia and Big Pino. He and Chrome created illusions to hide themselves, and another one to fight Small Gia and Big Pino to buy some time until Tsuna, Enma, and Basil arrived after defeating Alejandro. However, Small Gia and Big Pino were able to pinpoint their location, destroying the illusions, Gokudera's Sistema C.A.I and Yamamoto's swords. Fortunately, before Big Pino was able to kill them with his next attack, they were saved by Enma's gravity manipulation that made them float in the air, dodging the attack.
When Yamamoto and Gokudera were able to hold Small Gia and Big Pino with Enma's help, Chrome told Fran to protect them with Verde's equipment. Fran was, at first, reluctant due to being tired, scared, and annoyed. But he quickly relented when Chrome firmly insisted that he must help, on one condition: that she will kiss him on the cheek if it goes well. With Chrome's aid, he created ceramics that covered Yamamoto's and Gokudera's entire bodies right before the dynamites explode, destroying Small Gia's and Big Pino's power without harming Gokudera and Yamamoto. After resting, he went to assist the members who were fighting Jaeger and protected Tsuna from Jaeger's attack, but was quickly defeated by the latter along with Chrome and Enma.
After the Representative Battle was finished, he was admitted into Namimori hospital along with Mukuro, Chrome, Byakuran, Hibari, Dino, Basil, and the Varia. He appeared when the wall that connected to Mukuro's room was destroyed by Hibari's tonfa, commenting how Hibari's tonfa hit right at the spikes of Mukuro's hair. In the last chapter, he was seen with the rest of the Kokuyo Gang when Tsuna narrated his thought of now having reliable friends.