Fresh off his win at the Violet City Gym, Ash and friends encounter a Marill that cries at everything. Following an encounter with Team Rocket, Misty, Togepi, and Marill become separated from everyone after being washed away in a river. Now Misty must somehow get back to Ash and the others while at the same time passing all of the many challenges of a forest.

Ash and friends meet a girl named Liza, the person who protects the nearby Charicific Valley, a valley where wild Charizard live. Everyone goes there and Ash wants his Charizard to train with the others, but after it is easily beaten by another one, it loses its fighting spirit. Now Ash must figure out what is the best thing to do for Charizard.