Ash, May, Brock and Max have arrived at a small city on their way to Rustboro City. Brock decides to stock up on supplies, while Max is eager to go hunting for city dwelling Pokémon. Max soon stumbles upon a very frightened Shroomish who is hiding in an alleyway. Ash, Max, Pikachu and their new Shroomish friend head off to find a Pokémon Center.

As our heroes travel on towards Rustboro City, they stumble into a forest filled with many different kinds of Pokémon. It turns out that the area is actually a Pokémon preserve, and it's looked after by a girl named Katrina. Katrina takes care of all of the Pokémon in the area and helps to nurse them back to health when they are sick. Max takes a particular liking to her Poochyena and he's determined to see it evolve before they leave the preserve.