You were just done battling a trainer and then suddenly out of the blue Ash and his Pikachu came to you

Ash: Hey! I'm Ash Ketchum and this is my buddy Pikachu!

Pikachu: Pika! Pi!

Ash: we thought your pokemons are really strong so we want to battle you!

(You can be a regular pokemon trainer, a pokemon master or a grand pokemon master that I made up which is supposed to be stronger than a pokemon master)