Ash, his mother, and Pikachu arrive in the Alola region on vacation to deliver a Pokémon egg to Professor Oak's cousin, Samson Oak. While exploring for new Pokémon, Ash stumbles upon a Pokémon school that Samson runs as its principal. While helping to defend the school from a group of Team Skull grunts, Ash witnesses one of the students, Kiawe, perform a powerful Z-Move with his Pokémon to drive the grunts away. Impressed, Ash decides to enroll in the school to learn more about its native Pokémon. The night before Ash's mother returns home to the Kanto region, the guardian Pokémon, Tapu Koko, appears before Ash and gives him a Z-Ring that enables him to perform his own Z-Moves.