Grappling sport SUMO is a traditional Japanese martial art and competitive sport. It is a full-contact wrestling sport in which two opponents attempt to force each other out of a circular ring or into submission. The sport originated in Japan, where it is still practiced today. SUMO wrestlers wear mawashi, a type of belt, and use various techniques to push, trip, and throw their opponents. The objective of the sport is to force the opponent out of the ring or make them touch the ground with any body part other than the soles of their feet.