Mayumi Kinniku is the father of Ataru and Suguru Kinniku and the 57th King of Planet Kinniku. He has the character 王 (Ō 王) written on his forehead. He is a former Chojin Olympic V2 Champion as well as a Universal Grappling Champion. He has a fierce and long-standing rivalry with Harabote Muscle (the future chairman of the Chojin League), and the two of them frequently appear in Exhibition Matches which are unpopular with the younger fans. His name comes from Akinobu Mayumi.