Mari was bullied by her unrelated stepmother and step-sisters. The only thing that soothed her was the otome game "Rhapsody". One day, while playing the game, a hidden scenario appeared. After playing for a while with Annette, the villain princess who is the protagonist of the hidden scenario, the game screen suddenly went dark. Just when she thought it was a malfunction, a black gate appeared in front of her and Mari was sucked into the gate. Then, when she came to her senses, she had become Annette, the villain princess. If the game scenario proceeds according to plan, Annette will be killed eventually. In order to avoid death, Mari uses her knowledge of the game to change the scenario.