18-year-old Ryuusei Hananosuke, the younger brother of the 17th shogun Tokugawa Iemaro, is a masterless ronin who devotes his life to games. Hanabinosuke's 42-year-old nemesis, Akuinata Motonosuke, brought along Hanabinosuke, a mechanical doll for fighting games, custom-made by a puppet craftsman in Nagasaki!! It is said that it is an invincible doll set to surpass Hananosuke's ability, but...!?