Gray Wall Gear: The stage of this work is Saitama, a suburb of Tokyo in the early Heisei period. Immediately after the bubble burst gangster countermeasures law, there were gangsters who defended the last territory and young people who freely controlled the city. The youth conflict escalated day by day and became a force that surpassed the yakuza, and the runaways were sent to juvenile prisons one after another, where exclusive rules awaited.