The protagonist is reborn as Ruivel, a background character and princess in the fantasy novel Legend of the Hero of Light. Even though she was supposed to be a minor character, Ruivel suddenly receives a marriage proposal from the novel’s hero, Heizen. Thinking she might have changed the original story, she feels overjoyed and begins living a happy life. But one day, she catches Heizen cheating on her. That’s when she realizes this world isn’t the novel at all, but actually a terrible game based on it. In this version, she’s nothing more than one of the love interests meant to be tossed aside by Heizen. Fueled by anger and a desire for revenge, Ruivel meets Ancelot, the prince of a neighboring kingdom who is infamous as a bloodthirsty killer. "You want revenge on him, don’t you? Then use me, Princess."