When Lawrence III's scheme to capture the Legendary Pokémon Lugia upsets the balance of nature, it is up to Ash Ketchum and his friends to save the world.

When the sadness of her father's disappearance gets to Molly Hale, she unknowingly uses the Unown to create her own dream world along with Entei, who she believes to be her father. When Entei kidnaps Ash's mother, Ash — alongside Misty and Brock — invade the mansion looking for his mom and trying to stop the mysteries of Molly's Dream World and Entei!

Ash Ketchum wakes up late one morning after having broken his alarm clock in his sleep. He eventually makes it to Professor Oak's lab, but is told that the three starter List of Pokémon (Bulbasaur, Squirtle, and Charmander) have already been taken by Trainers who were on time. However, Oak reveals that he has one more Pokémon, an Electric-type named Pikachu. Despite its volatile and feisty personality, as well as its refusal to get inside a Poké Ball, Ash happily takes Pikachu for his journey.

Signal, a robot companion built for Nobuhiko, is attacked by Pulse, one the its creator's previous prototypes. Reprogrammed by Dr. Otoi's mysterious rival, Pulse is loaded down with weapons and sent on a mission by Otoi: steal the most recent robot technology, and obliterate anything that gets in his way.