On Earth, individuals reside in a society where vampires exist and pose a genuine threat to their safety. Despite humanity's ability to maintain control over these creatures and eradicate their natural nocturnal habitat, a new kind of vampire, Hesperides, has emerged. These vampires have evolved over centuries, allowing them to venture outdoors during the somewhat mild dusk hours and prey on humans.
Living in a town where vampire assaults haven't occurred in years, Aburaya Shiro, a high school student, and his peers are cautioned against going outside during dusk. Nonetheless, they disregard these warnings and go out, only to discover that one of their classmates, someone they believed they knew well, is a Hesperides. After witnessing all of his classmates' gruesome deaths, Shiro's only chance of survival is with the help of Ichijoji Eruka, a fellow classmate who appears to be unlike any human being.
