Sumo is a traditional Japanese form of wrestling that dates back to the Edo period (1603-1868). It is a full contact sport in which two opponents attempt to force each other out of a circular ring or into touching the ground with any part of their body other than the soles of their feet. SUMO wrestlers, known as rikishi, wear traditional mawashi belts and are divided into six divisions based on skill level. The sport is highly ritualized and is accompanied by many Shinto traditions.