The near future witnesses Earth under attack from extraterrestrial beings, which prompts the United Nations to draft all able-bodied humans as soldiers. Despite his frail physique, high schooler Kurando Nieno is not exempt from this recruitment process. However, his low scores on the physical exam paint him as an unlikely candidate. During one of the alien air raids, a bad-tempered girl with ebony locks crashes in front of Nieno and tries to feast on his blood. Eliza, the vampire, alongside the United Nations air force, singles out Nieno as the perfect source for her sustenance.
