In this continuation of the Pokémon series, following his mother's victory in a vacation raffle to the Alola region, Pokémon trainer Ash and his partner Pikachu arrive at Melemele Island, home to unique Pokémon and variations of familiar species. Eager to explore, Ash and Pikachu get lost while chasing a Pokémon and find themselves at the Pokémon School, a place dedicated to learning about Pokémon.
Here, Ash encounters Kaki, a determined student, during a confrontation with Team Skull, which reveals the potency of Z-Moves—powerful techniques exclusive to the Alola region that demand perfect synchronization between trainer and Pokémon. That night, Ash and Pikachu meet Kapu Kokeko, the guardian deity of Melemele Island, who presents them with a Z-Ring, essential for performing Z-Moves. Inspired by their recent experience and now equipped with a Z-Ring, Ash and Pikachu choose to remain in the Alola region to learn and master these formidable abilities.
Joining the Pokémon School, Ash becomes part of a diverse class including Lillie, who adores Pokémon but struggles to physically interact with them, along with Kaki and other classmates. As they attend classes, fend off Team Rocket, who have also arrived in Alola to advance their organization's goals, and undertake the Island Trials needed to hone their Z-Move skills, Ash and Pikachu embark on an exhilarating new journey.