After being pushed by her father, Yui Komori moves to an isolated mansion where the Sakamaki siblings reside, including Shuu, Reiji, Ayato, Kanato, Laito, and Subaru. Being a family of vampires, the brothers are somewhat taken aback but then realize that Yui is their newest "sacrificial bride," and they aim to claim her in more ways than one. While getting to know each brother, Yui starts to get more curious as to why her father sent her there and begins to feel an unexplainable ache in her chest. The siblings become increasingly malevolent, and Yui is stuck in the mansion, living a nightmare. Every night, each brother tries to take her, and Yui is losing her mind as she spirals further down into the abyss.