Tomomi Isogai, a male figure with auburn hair and brown eyes, rises as the self-proclaimed “archangel” and second-in-command of Ikebukuro’s Red Angels gang. Behind his disarmingly friendly and sensitive exterior lies a calculated operative for the Kansai-based Kyougokukai yakuza, embedding himself to covertly advance their drug and firearm trafficking interests. Tasked with destabilizing rival factions, he engineers gang warfare by supplying firearms to the Red Angels and their adversaries, the G-Boys, while discreetly surveilling perceived threats like Makoto Majima through a spy app.

His vengeful agenda stems from a tormented past: severe bullying in Ikebukuro schools drove him to abandon his education, flee to Kansai, and pledge allegiance to the Kyougokukai. Returning undercover, he exploits his Red Angels position to target former classmates—unrecognized by them—and manipulates allies like Mitsuki Fujimoto into orchestrating assassination attempts, intensifying territorial chaos.

Exposure by Makoto halts the conflict, unraveling his dual allegiances and culminating in his arrest for murder and assault. Though fueled by loyalty to the Kyougokukai and a personal crusade against past tormentors, his schemes collapse under scrutiny, leaving Ikebukuro’s underworld reshaped by his betrayal.