Kiryu Kazuma was brought up in the Sunflower Orphanage, and has been protected since his childhood by a lieutenant of the Dojima Family, affiliated with the Tokyo-based Tojo Clan of the Japanese organized crime syndicate, the yakuza. His back covered with a tattoo of a dragon, Kazuma soon becomes a prominent member of the Dojima Family - until he takes the blame for the murder of its leader in order to protect his best friend, and is sent to prison. Ten years later, Kazuma returns to his home town Kamurocho. He finds out that Yumi Sawamura, a young woman he grew up with in the orphanage, has disappeared. Ten billion yen has been stolen from the Tojo Clan, and various yakuza groups are searching for the money everywhere. Against his will, Kazuma becomes involved again in the struggles and intrigues of the yakuza world.
