The young Jin Kambayashi, still a cadet for the Suna clan, tries to shoot the second head of the rival Kurokawa clan, but accidentally shoots Yoshiro Yazaki, a young man who has nothing to do with the yakuza, in the leg. Yoshiro, an activist with dashed dreams of revolution, resonates with Jin's simple, straightforward way of life and volunteers to become a yakuza. Meanwhile, Onimaru, a young leader of the Kurokawa clan, has murdered the second head of the clan and is about to pin the crime on the Sunagumi.
