Kamiya Genjiro is an extraordinary policeman. His intelligence and analytical mind see him solving all the crimes in the town of Kitamachi, during the Edo period. His good-for-nothing boss assigns all cases to him, as Genjiro is relentless in resolving the crimes. However, there is one crime that Genjiro is dying to resolve, and that is murder of his mother and sister 14 years ago. At that time, the magistrate in charge had let the case go unsolved due to pressure from the powers-to-be. The only clue Genjiro has is that it must be someone powerful, in order for the magistrate not to pursue the matter.