Ritsuka Tachibana leads a quiet, unremarkable existence. Her elder brother Lindo returns from the United Kingdom after completing his studies abroad. The student council president of Shikou Academy, Rem Kaginuki, summons her, and she soon encounters the council members in uncanny ways. That day altered her routine slightly, yet Ritsuka anticipated nothing further. Yet one evening she arrives home to discover her mother collapsed beside a group of hooded figures. They were not ordinary humans but devils, vampires, and exorcists hunting the Forbidden Grimoire. The familiar rhythm of her life shattered, and she gradually develops feelings for Rem, who supports her through the crisis. Her heart beats faster whenever Rem's eyes meet hers. Simultaneously, uncertainty grows over her brother, who keeps a hidden secret. Ritsuka stands at the crossroads of love and mystery, unsure which path to pursue.
