Strike the blood

"Koju Akatsuki lives on the artificial island of Itogami, and has secret: He's the 'Fourth Primogenitor,' the most powerful vampire in the world. He's carefully kept this dark knowledge from his family and friends, but one day, a beautiful girl named Yukina Himeragi appears before him and tells him that she knows who he really is--and that she's been sent to... kill him?!"--Back cover.