Ryuunosuke's from an impressive clan… Or well, his secret is impressive, but he's not. After receiving a an unknown vampire doll from his sempai, his spilled blood wakes it up. With the soon-after death of his dear colleague, he also acquires a beautiful meat-eating girl. These two girls guide Ryuunosuke in controlling the monster that lurks within his blood while he tries to figure out the true reason for his existence.