A listless Wade Wilson toils away in civilian life with his days as the morally flexible mercenary, Deadpool, behind him. But when his homeworld faces an existential threat, Wade must reluctantly suit-up again with an even more reluctant Wolverine.

Kou Yamori is a middle school student who struggles with grasping the complex concept of love. Plagued with insomnia due to his idleness, Kou begins roaming the lonesome streets at night.

One night, Kou encounters a bizarre girl named Nazuna Nanakusa who believes that people stay awake during the night because they are dissatisfied with how they spent their day and cannot rest until they release their inhibitions. Nazuna offers to help Kou with his sleep issues and invites him over to her place, where she convinces him to share a futon with her. Feeling uncomfortable, Kou only pretends to doze off—which is when Nazuna suddenly bites his neck, revealing herself to be a vampire!

While Kou thinks the bite will turn him into a vampire, the specifics of transforming are not that simple. In order to change, he must be bitten by someone he truly loves. Ready to let go of his dreary mortal life, Kou decides on a new goal: he will fall in love with Nazuna and become a vampire himself.