Ko Yamori is a second-year junior high school student who doesn’t have much interest in girls, and for some reason or other, has stopped attending school. Additionally, he’s developed insomnia and hasn’t slept a wink in days. One night, he decides to slip out at night without telling anyone. The night breeze feels good and he has a sense of endless freedom. It’s an entirely different world from the daytime and Ko is able to find a place where he belongs at night. However, that’s where a mysterious beautiful girl named Nazuna Nanakusa suddenly appears. She’s a vampire and teaches Ko about the pleasures of nighttime.

“Let’s stay up all night until you’re satisfied, boy.”

Fascinated by the nighttime world and Nazuna, he makes an earnest request: “Please turn me into a vampire.” While blushing, Nazuna tells him that in order for a human to become a vampire, they must fall in love with one. Knowing nothing about love, will Ko actually be able to fall for Nazuna and become a vampire? The story of these two night owls and their special nighttime exploits begins.