From Bulbapedia, the community-driven Pokémon encyclopedia.
An overhead view of the tournament
The Pokémon Sumo Tournament is a competition in the anime that is held during the Grand Harvest Festival on Harvest Island. It was featured in The Journalist from Another Region!.
The Pokémon Sumo Tournament was established when a Beartic and Ursaring of Harvest Island folklore fought. Since then, other Pokémon participated as well. The winner of the tournament receives a Focus Band and a lifetime supply of some fruit.
Pokémon used in the tournament