Sumo wrestling is the National Game of Japan. It originated in ancient times as a performance to entertain the Shinto deities. Many rituals with religious background, such as the symbolic purification of the ring with salt, are still followed today. In line with tradition, only men practice the sport professionally in Japan.
The rules are simple: the wrestler who first exits the ring or touches the ground with any part of his body besides the soles of his feet loses. Matches take place on an elevated ring (dohyo), which is made of clay and covered in a layer of sand.