The first grand tournament of Ozumo, professional sumo in Japan, is held in January. Currently Ozumo has six grand tournaments or honbasho in each year. Three of them are held in Tokyo, and the rest in Osaka, Nagoya and Fukuoka. Hatsubasho or the first grand tournament in a year is held in January at Kokugi-kan, Tokyo. Ozumo also has irregular small tournaments in many cities in Japan and occasionally in foreign countries. Sumo is a Japanese traditional martial art, and today it is regarded as the Japanese national sport. Its history goes back more than one thousand years. It is well known to the world as a type of wrestling where men, dressed in loincloths, known as mawashi, try to push or pull their opponent out of the clay ring, or to get them to touch the ground with any part of their body, other than their feet. Sumo has been connected to the Japanese native religion, Shinto, and used to be held at shrines. Accordingly, modern sumo wrestling inherited some old sumo traditions. For instance, the current professional sumo organization, Nihon Sumo Kyokai, still does not allow women to step in its ring or dohyo, a rule that sometimes creates controversy.