Doushitemo Eto ni Hairitai
どうしても干支にはいりたいDoushitemo Eto ni Hairitai
The story
ONARat, a member of the Zodiac, meets a normal cat at a park one day. Rat comes to love Cat so much that it becomes very eager to get Cat to become a member of the Zodiac. Cat goes with Rat to meet the rest of the 12 members of the Zodiac to ask them to become a member.
(Source: ANN)