Ash tries to capture a Hitmonchan, but it actually has a trainer. This man, Anthony, is very competitive and spends all his time training his fighting Pokémon for a big fighting Pokémon tournament. Anthony's daughter, Rebecca, secretly asks Ash and his friends to beat Anthony's Hitmonchan, because her father is not spending enough time with his family. So Ash enters the competition with Primeape, and Brock with Geodude. Meanwhile, Team Rocket steals a Hitmonlee and enter with that.
The competition is fierce, and Primeape, acting on its own accord, is thrown right out of the ring... but Ash dives to save it. Touched that his master would injure himself to protect it, Primeape now obeys Ash. Together, they beat lots of competitors, while Geodude is instantly defeated. When Rebecca dives to save her father's Hitmonchan, her father dives to save her. By cheating, the Rockets' Hitmonlee beats Hitmonchan, and the finale is between Hitmonlee and Primeape. Primeape just manages to come out on top. Anthony realises his family is more important than obsessive training. Ash leaves Primeape with him so that he can truly become a strong fighting Pokémon!