For anyone who doesn't get it: In some eastern cultures they have tales about a rabbit on the moon pounding rice cakes/mochi/some other food stuffs. It's based off the markings on the moon (similar to how in some western cultures we see a "man" on the moon)
http://moon-rabbit.com/wp-content/uploads/Legend-rabbit01.jpg
http://moon-rabbit.com/wp-content/uploads/Legend-rabbit01.jpg