Office worker and 40-year-old virgin Minoru Sayo lives a simple, perhaps boring, life—at least until the day he is turned into a vampire.

Meanwhile, his psychopathic junior colleague Yamadera is dead set on doing whatever it takes to become a vampire, including throwing himself in front of a train. Minoru jumps into action to protect him, but the damage to his body has a very unfortunate side effect—it further awakens his vampire instincts!