Pokemon: Pikachu, Kore Nan no Kagi?
Plot Summary: The Key Pokémon Cleffy appears before Pikachu and friends! When keys that possess mysterious powers are inserted into the keyholes floating in mid-air, the keyholes light up and expand and a magical subspace spreads out before the Pokémon! Cleffy has keys that lead to all kinds of worlds. What kind of world does the key Pikachu receives take the Pokémon to?
Other name: ポケモン・ザ・ムービーXY『ピカチュウ, これなんのカギ?』