Ash heads to the Canalave Gym for a battle, but the Gym Leader is not there, and all of his pupils are fast asleep. After bumping into Officer Jenny, they find out that a bunch of people in town are having nightmares. They decide to help find the source, and it leads to Team Rocket. They have created a machine that gives everyone nightmares, and thus makes the citizens want to buy what they believe to be real Lunar Wings. Ash, Dawn, Brock, and Jenny manage to destroy the machine, but that night they still have nightmares. With no other option they head to Newmoon Island to find the legendary Cresselia, hoping she can help.
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.