Sumo is Japense-style wrestling which has long history and it was practiced as a part of Shinto ritual in ancient time.
Sumo is Japan's national sports and is popular especially among elderly people.
Sometimes sumo mathces were held to build temples and shrines in the past. Professional sumo wrestlers appeared in the Edo period and some of them were hired by feudal lords.
In sumo matches, 2 wrestlers wearing only mawashi, or loinclothe wrestle in the 4.5 meter diameter ring until one of them is pushed out or touches the ground with any part of his body other than soles of his feet.
While there are over 60 official kimarite, only a dozen or so are seen regularly.
There are 6 tournaments lasting 15days every year, 3 in Tokyo, 1 in Nagoya, Osaka, Fukuoka, respectively. You can buy a ticket on the internet.
Tokyo basho is held at Rogoku Kokugikan, It's a 1 minute walk from the JR Sobu Line, Ryogoku Station. On the 1st floor of Ryogoku Kokugikan is a sumo museum.
First famous foreign wrestler is Takamiyama, and first yokozuna, grand champion is Akebono, they both are from Hawaii. In these days, there are many foreign wrestlers and 3 present Yokozuna are all Mongolian.