Bottom-rung working girl Lin Wanwan saves the injured wealthy young master Lu Tingchen in an alley, and is hired by him the next day as a fake girlfriend for a "50,000 daily salary" to resist family arranged marriages. Short of money, Lin Wanwan agrees, unaware that she looks very much like Lu Tingchen's late sister. In one "business" session after another, Lin Wanwan unexpectedly wins Lu Tingchen's true heart with her authentic and sharp-tongued personality. Meanwhile, Gu family adopted daughter Gu Yurou notices the cloud-shaped birthmark on Lin Wanwan's arm, and is horrified to discover that she is precisely the Gu family's true granddaughter lost for twenty-three years, Gu Yue.