"Ouroboros" is a historical emblem which portrays a snake eating its own tail - significance infinity. Based on a popular comedian book, a clumsy detective and also a gang that is trendy stand upto wicked. Tatsuya and ikuo climbed up in a children's orphanage. If their educator, Yuiko, is murdered, the incident is covered by a policeman wearing a golden watch. Tatsuya and ikuo assert one another to avenge their educator someday. Twenty five years after, Ikuo is a detective in Shinjuku 2nd police channel investigating cases that are various with elite detective - Mizuki, while handsome and bright Tatsuya has become one of the members of a gang group.