Misao Harada has been able to see demons since she was a child and has vague memories of a boy who protected her from these troublesome creatures, vowing to come back for her someday. Now in high school, Misao wishes she could be normal and have a boyfriend. As she returns home one day, she notices a gorgeous stranger has moved in next door. To her surprise, he introduces himself as Kyou, her long-lost childhood friend and first love.

The next day, on her 16th birthday, Misao is suddenly wounded by a classmate. Exposed as a demon, he plans to eat her in order to gain eternal youth. When all hope seems lost, Kyou saves her, revealing himself as the leader of a Tengu clan. Since making Misao his bride will bring prosperity to his clan, he offers her a choice: sleep with him and become his bride, or endure more attacks from other demons drawn to the power of her blood.