A woman from the modern world dies in a traffic accident and reincarnates into the body of Petra, one of Cinderellas stepsisters. Aware that she is living inside the classic fairy tale, she uses her prior life's driven and hard-working personality to ensure the story proceeds according to script. Cinderella is beautiful but exceptionally lazy and sloppy, so Petra and her other stepsister take it upon themselves to rigorously educate the girl, hoping to mold her into someone the prince would marry. However, their strict methods are misinterpreted by onlookers, earning them the reputation of being the wicked stepsisters.

Their plan succeeds, and Cinderella marries the prince, achieving her happy ending. Believing her role in the story is complete, Petra expects to finally relax and live a quiet life. But at a celebratory ball, she encounters a mysterious and blunt gentleman named Eric. He confronts her directly, accusing her of bullying Cinderella out of petty jealousy. Far from being a meek villain, Petra refuses to accept this false accusation and fights back. This tense encounter ignites a spark of romantic tension between them, filled with sharp arguments and undeniable chemistry. The central conflict becomes Petras struggle to break free from her unfair reputation and discover what kind of happy ending might be possible for the evil stepsister when the original fairy tale is already over.

The story is set in the familiar world of the Cinderella fairy tale, reimagined through a contemporary lens. The main cast includes Petra, the reincarnated protagonist who is practical and loyal; her fellow stepsister who shares her burden of the villainous label; Cinderella, who is portrayed as beautiful but messy; and Eric, whose accusations hide a deeper interest in Petra. The prince also appears, but primarily to fulfill his classic narrative purpose and step aside, allowing the story to focus on the stepsisters fate. Notable narrative arcs include the completion of the initial mission to marry off Cinderella, followed by the fallout as Petra navigates her post-fairy-tale life. The core of the story lies in the enemies-to-lovers romance between Petra and Eric, fueled by misunderstandings and verbal sparring, as Petra fights to assert her own identity and prove that even a supposed villain deserves a future of her own choosing.