Blood: The Last Vampire.

On the surface, Saya is a stunning 16-year-old, but that youthful exterior hides the tormented soul of a 400-year-old "halfling". Born to a human father and a vampire mother, she has for centuries been a loner obsessed with using her samurai skills to rid the world of vampires, all the while knowing that she herself can survive only on blood like those she hunts.