Ryuuji and his little brother were raised by a woman after their Yakuza parents were killed by a rival Yakuza gang. One day, he comes home and finds that his adopted mother too was also killed by that same gang. In rage and despair, he kills two Yakuza gang members who were still at the house and gets sent to jail. Once in jail, the inevitable happens and he becomes the plaything of fellow inmates; especially peaking the interest of one dangerous convict.
After spending time in jail, when everything seems lost, he meets a man by the name of Araki, who claims to be the brother of his deceased adopted mother. A special bond develops between the two; but what will happen once Ryuuji learns that the man, Araki, is the only surviving member of the Kazama gang – the gang that his father used to belong to? Will Araki-san, the dragon, be able to keep Ryuuji safe, or will his enemies the members from the rival gang, use the young man as a pawn against him?