Shohei Saji, a former member of the Roppongi street gang Lone Wolf, has left his old life behind and now works as a trainer at a boxing gym. When former gang member Inose is taken hostage by the Shinjo-gumi, Saji agrees to join the yakuza group in exchange for his friend's release. Forced to endure increasingly abusive treatment, he struggles to remain calm until one incident pushes him past his limit.