Having arrived at his new Pokémon school, Professor Kukui, who is the teacher, and its students host a surprise welcome party for Ash. Soon after, the guardian Pokémon, Tapu Koko, pays another visit to Ash to battle Pikachu. Tapu Koko teaches Ash how to use the Z-Ring. Ash and Pikachu manage to unleash the Z-Move, Gigavolt Havoc, but the Z crystal is soon shattered after Pikachu's immense release of power. In order to regain the power of Z-moves, Ash decides to go through the island trials.