A wealthy businesswoman has spent years desperately searching for her long-lost daughter, unaware that her biological daughter has been working in an entry-level position at her own company all along. The young woman only wants to apply for educational assistance, but her adopted sister ostracizes and mistreats her, while her mother favors the adopted daughter and refuses to support her education. A birthmark on her shoulder becomes the clue to her true identity. The adopted daughter tampers with the identification documents in an attempt to steal her identity, and even schemes to send her away from the city and arrange a marriage for her. Refusing to accept her fate, the young woman quietly gathers evidence to prove her innocence. Just as the adopted daughter fights to seize control of the company, her biological mother walks into the boardroom carrying the authentic DNA test results. At last, mother and daughter reunite and join forces to clear up every misunderstanding.