Sumo is a traditional Japanese style of wrestling that dates back to the Edo period. It is a full-contact sport in which two wrestlers, known as rikishi, attempt to force each other out of a circular ring or into submission. The wrestlers wear mawashi, a thick belt made of silk or hemp, and use only their hands and feet to push, trip, and throw their opponent. Sumo is considered a national sport in Japan and is highly respected by its practitioners.