Aileen Lauren d'Autriche's engagement to Crown Prince Cedric Jeanne Ellmeyer collapses in public, and the shock brings back memories of her previous life: memories that tell her she is the doomed villainess of the otome game Regalia of Saints, Demons and Maidens. Rather than compete with the heroine for the prince and walk toward her character's scripted death, Aileen tracks down the game's final boss, Cedric's older half-brother Claude Jeanne Ellmeyer, the prince cast out to rule the demons, and sets out to win him over instead.