เนื้อเรื่อง

The era is Meiji. Sana Shirafuji, who lost her grandmother and is left alone in the world, knocks on the military's door to become a "Bride Thorn" to make a living. A "Bride Thorn" is a "ration" for girls known as "Vampdolls", who are specialized in combat. Unaware of this, Sana accepts the military contract out of desperation. On her first day of enlistment, she meets Yukine Hanafusa, a beautiful yet disdainful Vampdoll. Born into a noble family, yet cursed from birth as a Vampdoll, Yukine is persecuted and reviled as a “monster.” Shunned even by her own family, she loathes her bloodthirsty impulses and keeps others at a distance— rejecting Sana as well. Yet, little by little, Sana and Yukine open their hearts to one another. On the night of their first bloodsucking, they are startled to learn that the act brings heightened physical and emotional sensations. Awkward as they are, the two nonetheless share their first experience of bloodsucking together. Not long after that, during a certain operation, Yukine is rendered unable to fight. Standing in their way as an enemy is Satsuki—once, a trusted comrade……。