Wrestling
Sumo is a Japanese sport. It's a kind of wrestling. But it is very different from western-style wrestling.
Being a sumo wrestler means living a special lifestyle. Sumo wrestlers live in a 'stable', where they eat very big meals to put on weight. They also get up very early in the morning to train. If they go out in public, they have to wear special clothes, so everybody knows they are a sumo wrestler.
History
Sumo probably started as part of the Japanese religion Shinto. At Japanese shrines - or temples - men used to do a dance in which they wrestled with the gods. It was probably used for training soldiers, too.
The sport of sumo came much later. Sumo of today really started in the Edo period (1603-1898). Edo was the old name for Tokyo.
