Spoiler

Family Haru Nanakusa (Mother), Kabura Honda (Adoptive Mother)

Nazuna is a female vampire who likes the night itself more than the daylight. A certain day she meets with a fourteen-year-old boy called Kou Yamori. Kou is a guy who can't sleep very well every night, so to satisfy Kou's will, Nazuna shows him how to sleep very well at night. On the same night, Kou discovers that Nazuna is a vampire, and that makes Kou feel the will of becoming a vampire too, but the problem began here, because neither Nazuna nor Kou knows what is love, and it is required that Kou falls in love with Nazuna in order for him to become a vampire.