Detective Kikuchi is sent to Okinawa to investigate why a girl jumped from a window after shooting heroin. There, he encounters the usual assortment of addicts, dealers, pimps and sleazy American GIs.
Coming out of jail and hoping for a quiet life, Yokohama yakuza has to take the lead of his gang after the death of his boss. His small group is is taken in a crossfire between a big yakuza group from Osaka at war with the Tokyo alliance for the control of the city. He tries to keep to the old yakuza code but he is no match for the new thugs who live and fight without honor.
A gangster named Sagara killed a broker at the request of a friend named Oba, was arrested and spent eight years in prison. Now released, he wants to find out who squealed on him.
Fresh out of jail, a smart-mouth wise guy Goro takes the name “Big Brother Katsumata.” Not fitting in well with established gangs, he forms a rag-tag gang called “the Shinjuku Brothers.” The members of their gang are thugs who only wish they were traditional yakuza. When they turn up at the funeral for a gangster, they are not welcomed, but a senior boss intervenes to keep things calm. The boss of bosses invites them to join a respected local council of warlords. Katsumata is suspicious of why such powerful men would extend an invitation to lowlife like himself.