Maruo Kadoko is a supporting character introduced in the first season of the Duel Masters anime series. He is the father of Rekuta Kadoko, the best friend of the protagonist Shobu Kirifuda. Maruo owns and operates a popular local card shop in Shobu's town, a gathering place where children come to purchase cards and play Duel Masters. He shares a close relationship with Shobu's father, Shori Kirifuda, and after Shori's disappearance, Maruo encourages Shobu by telling him stories of glorious duels from the past. Maruo is a knowledgeable figure within the community, serving as a source of support and inspiration for young duelists. His card shop is a central hub for the characters, and his role is primarily that of a friendly mentor and shopkeeper. He also has an old friend named Daba, who later buys Maruo's former card shop and converts it into a bakery. Maruo Kadoko does not display any notable dueling abilities himself, and his development largely revolves around his relationships with his son Rekuta and the Kirifuda family.