Hello Kitty: Ringo no Mori to Parallel Town (2007)

Kitty and Mimmy fall through a hole and end up in a parallel world. It's identical to the one the sisters live in but it's inhabited by humans with transparent wings and pointy ears. Kitty becomes friends with Emily, a supermodel in this parallel world, and together they try to rescue Mimmy who has disappeared. Their search is hampered by Akuro--a black cat who has a mean streak.