Saotome Mondonosuke, "Hatamoto" (direct servant of the shogun), a handsome man with a scar on his forehead in the form of a crescent moon, a favorite of the shogun. He is a master of martial arts, who owns the style of Moroha-ryu seigan-kuzushi (fencing), Yoshin-ryu tai-jutsu (the art of fighting without weapons) and even military science, but in the era of Genroku (1688-1704) all these skills are not in demand, and this brings boredom to Mondonosuke. To dispel boredom, this so-called "bored gentleman" walks around the city, and when he hears about some incident, he rushes to the place and defeats evil with his invincible swordsmanship. Mondonosuke has a 17-year-old sister, Kikuji (Yukiko Kashiwagi), and Kikuji's lover, Kirishima Kyoya (Takao Kataoka), becomes his right hand.