BloodPlus

From Asaction

Blood+ is either a vampire show or it's totally not a vampire show, depending on who you ask. There's this girl named Saya, who has lost her memory of most of her life and is presumably important to fighting the vampire monsters, and this dude named Hagi, who plays the cello and is hot. And like they fight the vampire monsters. And stuff.

Also, Wiki is a stupidface for apparently not allowing "+" in the link titles.