Rabbit, white holding on a yellow crescent moon

Images of rabbits decorate many Japanese objects including a lot of hahsioki.

Rabbits are popular because in the Japanese folklore a rabbit pounding rice is said to live on the moon. He is making mochi (rice cake) for the festival of the moon in Automn (O-tsuki-mi). Some spots on the moon surface form indeed a shape that can be interpreted as the image of the moon rabbit working the rice.

The rabbit or hare is also one of the twelve Chinese zodiac signs which are also used in Japan. In the Chinese zodiac, it's the year of birth which determines the sign as follows :

http://en.wikipedia.org/wiki/Moon_rabbit

http://www.hashioki.com/

Tsukimi or O-tsukimi refers to festivals dedicated to viewing and admiring the moon. These festivals occur in September and October (the precise dates depend on the lunar calendar). Traditionally some long grass 'susuki' is put in a vase and special dango are offered to the moon on a kind of wooden base.

Tsukimi ceremony is often associated with the image of the rabbit, as a legend tells that a rabbit piling rice for the tsukimi-dango lives on the moon

http://en.wikipedia.org/wiki/Tsukimi