It's a 1,500 years old Japanese martial art, steeped in the Shinto religion. It's a fast and exciting sport with simple,easy to understand rules.
It's part of the World Games, and is on track for inclusion in the Olympics.
At last count, 84 nations have joined The International Sumo Federation, so it has evolved far beyond its Japanese origins.
Sumo is competitive contact sport. A match is played between two players, designated East and West.
They make the best possible use of the 4.55 meter diameter dohyo and fight, almost naked, using their full strength.
Competitions are open to men and women, however, no contest between man and woman is allowed.