The son of Oryo, president of the Shinsengumi. Ryuunosuke was sent to Shanghai at the age of ten to learn more about the world. He recently returned from Shanghai and brought a Yōkai named Nekomaru to Kyoto for registration. Ryunosuke is a bit odd and has a peculiar sense of humor, but he is nevertheless determined to help out the Mobile Shinsengumi. He seems to also have a crush on Yuko. In the 8th episode of the series he temporarily turns into a girl because Nekomaru killed him with soap and switched his soul with that of a female.