Sophia is a highly capable maid in the service of the Lorraine伯爵 family, and she bears an uncanny resemblance to the family's daughter, Ange, the young countess. Sophia has long used her ability to impersonate Ange when needed while working diligently for the family she feels indebted to. However, a certain incident drives Ange to take her own life. Determined to make the person responsible pay, Sophia resolves to infiltrate the Auvers Marquis household, where she is certain the culprit resides. She does so by assuming Ange’s identity and marrying into the family.

The setting is the Auvers Marquis estate, a place filled with potential enemies: five marquis sons, each with his own temperament and hidden motives. Sophia must navigate her new role as a fake fiancée while secretly investigating Ange’s death. Complicating matters, the current head of the family announces that the person Ange would have chosen will inherit the estate, sparking a competition among the five brothers for Sophia’s favor. As the rivalry escalates, Sophia’s search for the truth leads her to suspect a particular maid’s suspicious behavior. At Theodore’s birthday party, she is pressured to choose a partner, and the event is thrown into chaos by a major incident. Amid the confusion, someone uncovers Sophia’s true identity and approaches her with dangerous intent. The story unfolds as a blend of revenge, romantic tension, and suspense, with Sophia balancing her quest for justice against the growing attentions of the five marquis sons.