A young man named Kanna, a serial killer so infamous he has been dubbed the Reiwa-Era Jack the Ripper, wanders through life unable to find the love he desperately seeks. His path crosses with Mikage, a boy whose beauty is compared to a porcelain doll. Mikage offers Kanna the love he craves, but he harbors a dark secret: he is a vampire who feeds on human blood. In this world, those who have committed grave sins bear a physical mark on their bodies known as a holy mark, proof of their transgression and their fall from humanity. The story follows these two figures as they navigate a supernatural landscape where sin manifests visibly, and love is entangled with bloodlust and redemption. As their relationship deepens, Mikage’s tragic past is gradually exposed, particularly through the arrival of a gentleman named Tokitoki Soichiro, who claims to protect those who have been forced into sin. Soichiro reveals the names of Mikage’s lost twin siblings, Towa and Setsuna, unlocking a forbidden history that tests the bond between Kanna and Mikage. The narrative explores the meaning of love, the weight of past sins, and whether two broken beings can find genuine connection in a world marked by guilt and the supernatural.