What is sumo?
It's a simple game with simple rules:
If you get pushed out of the circle or anything other than the soles of your feet touch the ground, you lose.
That's it! that's the rules.
if you're looking for a history of sumo there are a lot of videos that can summarize it better than I can.
With that being said: Sumo is thought of as the oldest professional sport in the world and is believed to have originated as a sort of Shinto ritual to ward off evil spirits
But I'm no historian, I'm just a guy who wants to push people