
Joe Jojima was a Japanese vigilante who co-founded the JUSTIS and Kiryu-kai street gangs during the 2010s. Born in Tokyo, he befriended Hiroshi Tanahashi and Kazuchika Okada and helped form JUSTIS to battle the "color gangs" that dominated Kabukicho. After the yakuza tortured Okada and his girlfriend, Okada experienced a change in character and transformed JUSTIS into a common street gang, expelling Jojima in the process. Jojima went into hiding in Onomichi, where, in 2016, he was rescued from JUSTIS thugs by Kazuma Kiryu. Jojima and Masao Muraki enlisted Kiryu's help with fighting back against JUSTIS, and he formed the Kiryu-kai with Joe and Masao as his lieutenants. Ultimately, they defeated all "Six Lunatics" and won them over, and Okada joined the Kiryu-kai after revealing that he had misled JUSTIS only to draw his tormentor Scar Satsuki out of hiding. Joe and Okada reconciled, and, together with Kiryu and the Lunatics, they defeated Satsuki and Takeshiro Komei, resulting in the near-destruction of JUSTIS.