Japanese police detective Saburo Fujioka is suspected of corruption, demoted, and sent to the city of Kojin. Kojin is the scene of fierce fighting between rival gangs. Fujioka is assigned to investigate the death of the wife of gangster Tetsuo Maruyama of the Kozuka gang, probably at the hands of one of the Oka gang. During a gang gunfight, Maruyama is rescued by Detective Fujioka and the two become friends. But Maruyama insists on avenging his wife's murder, even if it means conflict with his new friend.