The Japan Sumo Association , sometimes abbreviated JSA or NSK, is the body that operates and controls professional sumo wrestling in Japan under the jurisdiction of the Japanese Ministry of Education, Culture, Sports, Science and Technology (MEXT). This means concretely that the Association maintains and develops sumo traditions and integrity by holding tournaments and tours. The purposes of the Association are also to develop the means dedicated to the sport and maintain, manage and operate the facilities necessary for these activities. Therefore, the JSA operates subsidiaries such as the Kokugikan Service Company to organize its economic aspects, the Sumo School to organize training and instruction or the Sumo Museum to preserve and utilize sumo wrestling records and artefacts.

Sumo is a form of competitive full-contact wrestling where a rikishi (wrestler) attempts to force his opponent out of a circular ring (dohyō) or into touching the ground with any body part other than the soles of his feet.