Ash, Pikachu, and their friends meet the mythical Pokémon Hoopa. The little Pokémon likes to use his talent to play harmless tricks on people. When its true power is released, it loses control and becomes the terrifying Hoopa Unbound.

When Ash, Pikachu, and their friends visit a desert city by the sea, they meet the Mythical Pokémon Hoopa, who has the ability to summon things-including people and Pokémon-through its magic ring. After a scary incident, they learn a story about a brave hero who stopped the rampage of a terrifying Pokémon long ago. Now, the threat that has been bottled up for years is in danger of breaking loose again! Can Ash help his new friend overcome the darkness within...or will a dangerous secret erupt into a clash of legends?—Chandan