Ritsuka Tachibana, a diligent student, is unexpectedly called before the student council, led by Rem Kaginuki, Urie Sogami, Shiki Natsumizaka, and Mage Nanashiro, who seem to view her as a troublemaker. Their true intentions are unclear, but it becomes apparent that they're hiding something. Ritsuka's world is turned upside down when her mother is kidnapped, drawing her into a complex web of vampire and devil politics, both searching for the "Grimoire." Her brother Lindo's return offers little clarity, as even he appears to be keeping secrets.