Pokemon the series: Sun and moon Misty and Fluffy's christmas

In the kanto region, Ash, Pikachu, and Ash's nieces and nephews (Penny, Andy, Jessica, and Justin) get help from their old friends to throw a special christmas celebration for Misty, her sisters, and her talking Riolu, Fluffy, by singing a christmas song in order for Lucari claus (a Lucario who delivers gifts to humans and Pokemon) to come.