When Yui Komori's father, a priest, is sent to work in Eastern Europe, she is left behind in Japan and directed to live with her distant relatives. These relatives, the Sakamaki brothers—Shuu, Reiji, Ayato, Kanato, Laito, and Subaru—are all ridiculously handsome but exceptionally cruel. What's more, they are vampires who consider the human Yui to be nothing but insignificant prey!

Forced to conform to the brothers' lifestyle, Yui starts attending school in the evenings like they do, but even in public she is not safe. They have no qualms about drinking her blood whenever and wherever it pleases them, disregarding the risks of her becoming anemic or dying altogether. She must also submit to each of their impulsive desires—whether they choose to use violence against her or act to satisfy their carnal desires. Throughout it all, Yui must grapple with her sanity and the possibility of loving one of the very brothers who torment her...