Alexandra, a ducal daughter executed as an infamous villainess, somehow reincarnates as a cat. She is taken in by Ophelia, a marquis's daughter abused by her family. Touched by Ophelia's affection, Alexandra learns to love for the first time. However, Ophelia loses her life to the betrayal of her younger sister Helena and her fiancé, the Third Prince Vincent, and Alexandra dies alongside her to seek revenge. But Alexandra is reborn as Ophelia one year before her death! 'Ophelia, I will definitely make you happy...!' To change Ophelia's tragic fate, Alexandra uses her innate courage and cunning as weapons to steadily trap Helena and Vincent. Furthermore, Prince Christoph of the neighboring Kingdom of Vesser, who initially approached Ophelia to use her, eventually becomes captivated by her...!? A splendid, devoted-love turnaround romance where a former villainess 'kitty' changes the fate of her beloved owner!