Hello Kitty: Ringo no Mori to Parallel Town
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.

Hello Kitty: Ringo no Mori to Parallel Town has 27 episodes.
As of now, Hello Kitty: Ringo no Mori to Parallel Town has finished.
Hello Kitty: Ringo no Mori to Parallel Town aired from October 2, 2007 to March 28, 2008.
Hello Kitty: Ringo no Mori to Parallel Town is a TV short with episodes around 9 minutes long, originally from Japan.
Hello Kitty: Ringo no Mori to Parallel Town premiered in Fall 2007.