ねこ・ねこ・幻想曲

"Shiro" is a black cat who loves her family very much. She loves them so much she wants to help them out in times of need and trouble but it s difficult to do this if she s just a cat. So one night, she wishes on the moon to make her able to help, and the next day, she has turned into a human girl. (Source: AniDB)