Ash Ketchum, a 10-year-old from Pallet Town, is finally old enough to receive his first Pokémon; however, he oversleeps and the only remaining Pokémon at Professor Oak's lab is a strong-willed Pikachu!

Ash rushes into Viridian City with his badly wounded Pikachu. When he arrives, the city’s on high alert for Pokémon thieves—thieves like Jessie, James, and Meowth of Team Rocket, a group of bad guys dedicated to stealing valuable Pokémon. While Ash waits at the Pokémon Center for news on Pikachu’s condition, Misty arrives, angry about the bike Ash wrecked—but she softens when she sees Pikachu wheeled out on a gurney. Suddenly, Team Rocket crashes through the roof of the Pokémon Center! While Nurse Joy transports Poké Balls to Pewter City for safety, Ash tries to fight off Team Rocket’s Pokémon, Koffing and Ekans. Ash is having no luck battling, so his Pikachu, still recovering, teams up with a bunch of other Pikachu at the Pokémon Center to blast Team Rocket out of the building! Jessie, James, and Meowth realize that Ash’s Pikachu is not your ordinary Pikachu, and decide that capturing it is now their top priority. With the bad guys taken care of, Misty joins Ash and Pikachu on their journey to Pewter City. While they’re strolling through Viridian Forest, a Caterpie makes an appearance. Ash sees an opportunity to catch his first Pokémon. Will he be successful?

Ash captures his first Pokémon, a Caterpie; Ash battles for and wins a Pidgeotto; Ash's Caterpie surprises everybody in his first battle against Team Rocket.

A young samurai challenges Ash to a battle; a swarm of angry Beedrill interrupt the battle causing Ash to flee and leave Metapod behind.

While in Pewter City, Ash challenges Brock to a battle; Team Rocket falls into a trap they built themselves.

A scientist leads Ash and his friends deep into Mount Moon to find the storied Moon Stone, which is said to increase the power of Pokémon.