Ash and the group have finally made their way to the city of Trovitopolis, which should lead them right to Trovita Island and the next Orange League gym! Everything seems normal until the earth cracks right beneath their feet and they find themselves in the sewer underground, and not alone. There seems to be some sort of a "monster" living there that has been terrorizing the town. Will Ash, Misty and Tracey be able to find it, before it finds them?
A young boy named Ash Ketchum embarks on a journey to become a "Pokemon Master" with his first Pokemon, Pikachu. Joining him on his travels are Brock, a girl-obsessed Rock Pokemon Trainer, and Misty, a tomboyish Water Pokemon Trainer who may have a crush on him. Ash and Co. end up traveling through various regions, including Kanto, the Orange Islands, and Johto, and then enter the Pokemon League competitions there.
Along the way, they run into many confrontations with Jessie, James, and Meowth, a trio of Pokemon thieves who are apart of an evil organization called "Team Rocket". But every time Team Rocket try to do their evil deeds, they fail thanks to Ash and his Pokemon.