The Japan Sumo Association (Japanese: 日本相撲協会, Hepburn: Nihon Sumō Kyōkai, JSA) is the body that operates and controls professional sumo wrestling (called Ōzumō, 大相撲) in Japan under the jurisdiction of the Japanese Ministry of Education, Culture, Sports, Science and Technology (MEXT). Rikishi (active wrestlers), gyōji (referees), tokoyama (hairdressers), and yobidashi (ushers/handymen), are all on the Association's payroll, but the organisation is run entirely by toshiyori (elders). The organization has its headquarters in Yokoami, Sumida, Tokyo.