The story tells of a group of samurai who were left leaderless (becoming ronin) after their daimyo (feudal lord) was forced to commit seppuku (ritual suicide) for assaulting a court official named Kira Yoshinaka, whose title was Kōzuke no suke. The ronin avenged their master's honor after patiently waiting and planning for over a year to kill Kira. In turn, the ronin were themselves forced to commit seppuku for committing the crime of murder.
Ryuta and Mineo Komatsu are brothers, both yakuza (gangsters). Mineo, although complicit in crime, even murder, wants out of the gangster life, hoping to become a successful singer instead. Ryuta loves his brother, but Mineo's possible defection presents problems for the gang, and Ryuta realizes he must kill his brother if he wants to survive.