In Country H, the Juvenile Law was revised to set the maximum penalty at life imprisonment. In exchange, underage offenders are sent to a rehabilitation facility known as the "Juvenile Reformatory." However, this purely nominal punishment has backfired, leading to a surge in juvenile crime and bullying.

Gen Amamori, a high school student living in Country H, suffers through brutal bullying every single day. One day, his beloved dog is mauled to death by a dog belonging to his bully, Kanemoto. Pushed past his breaking point, Gen snaps and inflicts a severe injury on Kanemoto, resulting in his incarceration at the Reformatory.

Even within the facility, Gen finds himself at the absolute bottom of the hierarchy, subjected to constant violence. However, a chance encounter leads him to become the protégé of Seiya Kojo, the strongest man in the Reformatory.

In a hellish environment where violence is the only law, can Gen survive? This is the story of a man crawling his way up from the very bottom.