Blood the Last Vampire

Blood the Last Vampire summary:

In the fall of 1966, tensions run high on the U.S. Air Force base in Japan on the eve of the Vietnam War. After a series of suspicious suicides in a nearby town, an additional threat has infiltrated the military compound - vampires. A covert team of government agents committed to the elimination of vampires dispatch a mysterious young woman named Saya who, in the guise of a schoolgirl, must uncover the origin of the demonic plague, eliminate the ghastly beasts and stop their reign of terror before time runs out. She is the last remaining original. taken from manga.com