Vampire Vixen.

When Kanzaki gets his first love note from a cute girl in another class, he's not sure what will happen. But the last thing he expects when he goes to meet his admirer is to get kicked in the face before he even says hello. It turns out that his admirer, Mari Setagoya, is a vampire and not a very good one, at that. After knocking Kanzaki out and trying to suck up his blood Mari admits that she can't handle the raw taste of blood very well. But she needs to drink life energy to survive, and one bodily fluid is as good as the next when it comes down to it. Kanzaki is all-too willing to oblige, but Mari has another secret. Along with a thirst for life energy and impressive leathery wings, Mari has another special ability, one which is about to awaken thanks to Kanzaki.