Koji Nagata once commanded the yakuza trio Kentaro, Ryo, and Kazuhiko before their coerced rebirth as the idol group Gokudols. His incarceration stemmed from the trio’s botched mission, a disaster that drained their syndicate’s finances and prompted boss Inugane to present a grim choice: ritual suicide or gender reassignment surgery.

While imprisoned during the Gokudols’ rise, Nagata secretly followed their careers, cultivating an unlikely obsession that signaled a departure from his hardened yakuza roots. His bond with Kimura—Kazuhiko’s ex-subordinate—fractured as Kimura’s fanatical devotion to Chika, Kazuhiko’s stage identity, sparked bitter clashes. The rift deepened when Nagata’s silence about their shared history enabled the Gokudols to manipulate a public scandal, framing Kimura for sexual harassment.

Nagata’s past remains shrouded in mystery, defined solely by his leadership role within the syndicate. His narrative presence underscores how the trio’s choices reverberate through the criminal underworld. He exists solely within the main storyline’s confines, absent from expanded media narratives.