Six major sumo tournaments (called honbasho) are held during the year—one on each odd month, each taking place over 15 consecutive days. Three of these honbasho are held in Tokyo at the famous Ryogoku Kokugikan in Sumida. The event is broadcast on NHK (Japan’s BBC), but watching it on the television can never replicate the intensity of sitting in silence among 10,000 fans as the sumo wrestlers poise behind the white battle lines, choosing their moment to lunge. See here for information on how to buy tickets and here for a brief introduction to the sport.
Event details are taken from official sources whenever possible. It is always prudent to check the official event website before attending to make sure that there have not been any changes. If you know of an error in the calendar, then please let me know through the contact form.