As a child, Kasama Ryuuji watched his parents killed before his eyes by the rival, Yazuka gang. As a teenager, he finds the woman who raised him after the death of his parents, raped and murdered by the same gang. With the lost of his loved ones, Ryuuji wants nothing more to do with the Yazuka. When everything seem lost, the kind and caring, Araki, who claims to be the brother who his adoptive mother appears. Ryuuji develops a special bond with Araki but how will Ryuuji react when he learns that Araki, in fact, is the only surviving member of the Kasama gang, who has devoted his life to protecting Ryuuji. Will Araki-san, the dragon, be able to keep Ryuuji safe, or will his enemies use the young man as a pawn against him?