Umon's services are called upon when innocent bystanders, Okayo and Minokichi, along with the ronin, Gontaro are mistakenly identified as suspects in several recent murder cases. To prove their innocence and uncover the truth, Umon launches his own investigation. Known as THE constable of Edo, Kondo Umon is a handsome and wise detective who uses his skills to catch the true perpetrator of vicious crimes. In addition to having to deal with the criminal element, he must also contend with the "Pock-marked" constable for the North Magistrate, Keishiro. A man as incompetent as he is ugly. Umon, together with his number one follower 'Talkative' Denroku must unravel the mystery before Keishiro can foolishly ruin the lives of the young lovers.