Awakening in a hospital room, Shiki Toono finds himself blessed with the unusual ability to perceive unseen lines that, when cut, obliterate objects in the world of Shingetsutan. Keen on keeping this power hidden, Shiki resumes his normal high school life until a chance encounter with a enigmatic woman with crimson eyes shatters his tranquility. After a bewildering event that seemingly involves her demise, Shiki is thrust into a perilous situation with demonic creatures. Fortunately, the woman, revealed as Arcueid Brunestud, a vampire royal, comes to his rescue. Forming an unlikely alliance, Shiki and Arcueid set off on a quest to unravel the secrets of their heritage and the recent town murders.