Yup. I'm surprised you haven't heard of the world's no. 1 shojo manga. :p
Basically, this girl, Tohru, ends up orphaned and inadvertedly moves in with her school chum Yuki Sohma, and accidentally finds out that 13 members of the Sohma family are possessed by the vengeful spirits of the zodiac and are able to transform into animals.
Thus, chaos ensues. :3