Wolfman is a Japanese Sumo Choujin who once held the title of Choujin Sumo Yokozuna, but later switched to Choujin Wrestling. He trains his muscles vigorously and boasts of his Beautiful Muscles of Steel(鋼の肉体美,Hagane no Nikutai-bi), muscles that exceed Kinnikuman's. At first he despises Kinnikuman and calls him Zeinikuman(ゼイ肉マン,Flabbyman), but after losing to him in a Sumo match he begins to respect his abilities. From then on he appears as an Idol Choujin and fights against the Akuma Choujin.