Pokemon XY: Odemashi Ko Majin Hoopa
English name: Pokemon: Hoopa, The Mischief of Pokemon
Genres: Action, Fantasy
Type: OVA, Episodes: 1
Aired: Jun 19, 2015
Studio: OLM
Source: Game
Rating: PG - Children
Synopsis:
An anime short for the Pokemon XY series. It is available in Japan along with the purchasing of a ticket for Hoopa and the Clash of Ages movie, which this short ties into. 

(Source: Bulbapedia)