An office worker and dating sim enthusiast dies in an accident involving her collection of romance games and awakens as Reine Waynewright, the protagonist of a fantasy otome game she never managed to finish. Her new life begins at a critical disadvantage. Reine is an F-rank student at Heartfelt Academy, a magical school where students are sorted by ability and those at the bottom are openly bullied and ignored by their potential love interests. She has no magical talent, no friends, and is on the verge of being expelled. The original Reine was so desperate that she attempted suicide, and the game narrative is heading toward a definitive Bad Ending.

Refusing to accept this fate, Reine claims amnesia to explain her sudden personality change and resolves to fight her circumstances through sheer effort. Unlike a typical isekai protagonist, she possesses almost no foreknowledge of the game's plot or hidden events, as she never completed it. Her only advantage is an adult’s determination to study, practice magic, and raise her rank through hard work. She is unexpectedly aided by Julius Waynewright, her aloof and handsome stepbrother who previously ignored her but now takes a puzzling interest in her recovery. Julius is possessive, secretive, and clearly knows more about her true place in the family than he reveals, creating an uncomfortable tension as Reine still believes him to be a blood relative.

As Reine begins to improve, she attracts the attention of several male classmates who fit otome game archetypes. There is Yoshida, a grumpy but talented student who becomes her reluctant study partner, and Reinhardt, a fellow underachiever she saves from bullying who reveals himself to be a hidden romantic prospect. She also encounters the prince of the academy, who initially snubs her. The school’s rigid ranking system from F to S forces Reine to compete in exams and practical tests, and her steady rise in rank draws both new allies and continued hostility from her bullies, particularly her cruel stepsister.

The story develops through several narrative arcs. The early volumes focus on Reine grinding for the rank exam, forming a study group, and slowly proving her worth. As she gains confidence, the mysteries of her situation deepen. Julius becomes increasingly possessive, interfering with her interactions with other boys and hinting that their sibling relationship is not what it seems. Reine learns that Julius has his own agenda involving revenge and may be using her as part of his plans. Later arcs take Reine away from the academy to the Waynewright estate for summer retreat, where she meets the dreaded cousin Cecil. Cecil introduces her to a strange girl who also calls herself a heroine, raising the possibility that another person has been reincarnated into the same game world. In a subsequent arc, Reine visits Yoshida’s family home and faces a challenge from his older sister, a test of love that forces Reine to confront her own growing feelings. Julius’s jealous streak intensifies each time Reine grows closer to another man, and he continues to hide the truth about their relationship, leaving Reine and the reader uncertain of his true intentions.