Pokemon: Pikachu, Kore Nan no Kagi?

Pikachu and his friends encounter the mysterious Klefki, whose collection of keys can open portals to wondrous places far beyond their own surroundings. Curiosity wins quickly, and the Pokémon follow the strange keys through one doorway after another.

Each key reveals a different realm and encounters with rare Mythical Pokémon, but the adventure becomes more complicated when the group is separated and one of the keys is lost. Pikachu and the others must find their way back together before the doors between these unusual worlds close on them.