Gu Yueling is in an eight-year secret relationship with her best friend's brother, Shen Mochuan. They've signed an eight-year contract—in public, she is his professional secretary. while in private, she is his darling lover. However, as the contract is about to end, Gu Yueling catches Shen Mochuan proposing to Wen Ling, a woman she happens to look strikingly similar to. Only then, does she realize that she was merely a stand-in for his "white moonlight." Heartbroken, Gu Yueling accepts to fulfill the arranged marriage proposed by her family to Su Xiujin, the heir of the Su Corporation. Unbeknownst to her, Su Xiujin has been in love with her for the past eight years.