Tokimeki Tonight

Fifteen-year-old Ranze Etou lives a normal life for any girl her age—except for the fact that she resides in a castle with a vampire father and a werewolf mother who constantly worry about her lack of powers. On her first day at a new school, Ranze meets the beautiful Shun Makabe and falls head over heels for him. While he remains oblivious, this does not stop Yoko Kamiya, the daughter of a yakuza boss, from becoming jealous. Furthermore, Ranze's parents despise the idea of her dating a human. On top of all that, Ranze has to cope with the manifestation of a new power—the ability to shapeshift into anything she bites! [Written by MAL Rewrite]

Since the television series ended years before the manga, the writers were free to write an original ending for the anime.