Japanese Sumo Wrestling, also known simply as Sumo Wrestling or Sumo, is a real life competitive full-contact wrestling sport where a Rikishi (wrestler) attempts to force another wrestler out of a circular ring (Dohyō) or into touching the ground with anything other than the soles of his feet. The characters literally mean "striking one another".
Sumo is generally considered to be a gendai budō (a modern Japanese martial art), though this definition is misleading as the sport has a history spanning many centuries. In Sumo competitions, a Rikishi attempts to force another Rikishi out of the Dohyō, a circular ring, or to touch the ground with anything other than the soles of the feet. There are also a number of other less common rules that can be used to determine the winner, for example a wrestler using an illegal technique automatically loses, as does one whose belt, or mawashi, becomes completely undone, or one who fails to turn up for his bout (including through a prior injury).
Matches consist solely of a single round and often last only a few seconds, as usually one wrestler is quickly ousted from the circle or thrown to the ground. However, they can occasionally last for several minutes. Each match is preceded by an elaborate ceremonial ritual.
Traditionally, Sumo wrestlers are renowned for their great girth and body mass is often a winning factor, since there are no weight divisions in professional Sumo, and considering the range of body weights in Sumo, an individual wrestler can sometimes face an opponent twice his own weight. However, with superior technique, smaller wrestlers can control and defeat much larger opponents.