Ryōgoku Kokugikan

To the uninformed sumo is two fat men in loincloths hugging and stomping like baby elephants trying to push each other over, to those with an appreciation of the sport it's seeped in honour, religious significance and tradition. Professional sumo matches are only held in Japan so if you want a chance to form your opinion in the flesh (lots of it), this is the only place to experience it.
The Ryogoku Kokugikan is where three of the largest annual sumo matches are held, the Hatsu Basho in January, the Natsu Basho in May and the Aki Basho in September. 10,000 spectators fill the sloping hall set up similar to a boxing ring with the raised platform of clay and sand where the match takes place in the centre. Traditional rituals and ceremonies are closely observed at these major bouts; starting on a Sunday and lasting for fifteen days the amateurs and novices are up first and competition progresses through to the masters, ‘winner takes all’ style.

When it’s their turn, wrestlers mount the sandy platform and perform a Shinto ritual to ward off evil spirits involving swaying and leg stomping then it’s on—wrestlers squat in front of each other, clap their hands as a show that they are weapon less and wait for the charge. In contrast to the extended ritual of the preparation a bout can be short, it often takes less than a minute for one of the combatants to be pushed out of the ring or touch the ground with anything other than his feet. On a day by day basis competition starts at around 9, the top division wrestlers arrive at about 4 and the highest ranking bouts take place at around 6. Cheap day seats are available on the upper levels, but if you get there earlier in the day you can give yourself a free upgrade to the morning bouts before most of the audience arrives. Ryogoku Kokugikan also has a sumo museum with hundreds of years worth of stories and relics of sumo history. The museum is free but closed on the weekends.
Ryogoku is Tokyo’s sumo central and matches have been held here for hundreds of years. Sumo gyms, or stables, where wrestlers live and train and restaurants serving chanko, the staple hot pot meal of wrestlers are grouped around this area and wrestlers are still expected to dress in traditional dress in public so they’re easy to spot (but even if they weren‘t dressed differently they would probably still be recognisable.). Some local stables let visitors watch early morning training which is a good alternative to seeing a match because you can get closer to the action.