In a deep, deep forest stands a school where girls reside. Their secret is that they are all 'vampires'. Emil, a cheerful and innocent girl who is sociable and loved by everyone. Eve, a solitary girl who speaks little, is unapproachable, and opens her heart to no one. In order to hunt and feed on blood without being discovered by humans, what has the 'sisterhood' formed by their blood ties brought to the two of them?