13-year old Gai Kudo is a youth uniquely obsessed with self-reliance and independence. Living on his own and struggling to survive, he finds some sort of peace and happiness standing apart from everyone else, despite his hardships. But after being framed for the murder of the rich president of the Hirata Group, Gai is sent to the "Human Institute", a prison for juvenile offenders that seeks to rehabilitate them through torturous methods.