Lan Zhi is exceptionally beautiful, and the heir of the Duke's estate, Gu Xingzhi, falls in love with her at first sight. Due to their difference in status and family pressures, Gu Xingzhi proposes to take her as a concubine. Lan Zhi, honoring her mother's dying wish to never become someone else's concubine, declares that she will only marry someone who truly wants her. The only one who comes to propose is the bookkeeper, Siyu. The two live in perfect harmony and deep affection. Gu Xingzhi obsessed with his desire, tries to forcefully take her, but Siyu's identity holds surprising secrets...
