Oto, also known as Yamatoo, was born as the grandson of a sumo wrestler, and was destined to become a sumo wrestler. His grandfather and master, Tamegoro Raiden, passes away, and the question of who will inherit the stable arises. While the chairman of the support association, Jumonji, plans to have the stable's signature sumo wrestler, Rainoumi, inherit the stable, the grandmother, the wife, is determined to have her grandson, Oto, inherit the stable