BLOOD THE LAST VAMPIRE

Teropterids are evil beasts which pose as humans and live only to drink human blood. Fortunately for the human world there are groups dedicated to destroying them. A brooding and mysterious girl named Saya is the best teropterid slayer there is, and now, in 1960's Japan, she is sent to a U. S. army base which may be infested...
(Source: Anime News Network)