Sumotori in Tokyo - Lafforgue

Sumo (相撲, sumō^?) is a competitive full-contact sport where a wrestler (rikishi) attempts to force another wrestler out of a circular ring (dohyō) or to touch the ground with anything other than the soles of the feet. The sport originated in Japan, the only country where it is practiced professionally. It is generally considered to be a gendai budō (a modern Japanese martial art), though this definition is incorrect as the sport has a history spanning many centuries. Many ancient traditions have been preserved in sumo, and even today the sport includes many ritual elements, such as the use of salt purification, from the days when sumo was used in the Shinto religion. Life as a rikishi is highly regimented, with rules laid down by the Sumo Association. Most sumo wrestlers are required to live in communal "sumo training stables" known in Japanese as heya where all aspects of their daily lives—from meals to their manner of dress—are dictated by strict tradition.

The demographic features of the population of Japan include population density, ethnicity, education level, health of the populace, economic status, religious affiliations and other aspects of the population.

As of March 2009, Japan's population is 127,076,183, making it the world's tenth most populated country. Its size can be attributed to fast growth rates experienced during the late 19th and early 20th centuries.

After having experienced net population loss over a number of years due to falling birth rates and almost no net immigration, and despite having one of the highest life expectancies in the world at 81.25 years of age as of 2006, Population decreased by 183,000 in 2009., The population of Japan in 2000, at New Year, was 127 million. Its population density was 336 people per square kilometer.

The population ranking of Japan dropped from 7th to 8th in 1990, from 8th to 9th in 1998, and from 9th to 10th since.

Ryōgoku Kokugikan (両国国技館, Ryōgoku Kokugi-kan^?), also known as Sumo Hall, is an indoor sporting arena located in the Ryōgoku neighborhood of Sumida, one of the 23 wards of Tokyo in Japan, next to the Edo-Tokyo Museum. It is the third building built in Tokyo associated with the name kokugikan. The current building was opened in 1985 and has a capacity of 13,000 people. It is mainly used for sumo wrestling tournaments (honbasho) and hosts the hatsu (new year) basho in January, the natsu (summer) basho in May, and the aki (autumn) basho in September. It also houses a museum about sumo. The venue is also used for other indoor events, such as boxing, pro wrestling, and music concerts. In past years, it has hosted the G-1 Climax, an annual tournament in New Japan Pro Wrestling.

Japan ⁱ/dʒəˈpæn/ (Japanese: 日本 Nihon or Nippon; formally 日本国  Nippon-koku or Nihon-koku, literally, the State of Japan) is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south. The characters that make up Japan's name mean "sun-origin", which is why Japan is sometimes referred to as the "Land of the Rising Sun".