The Jiang family of Beijing recognizes their true daughter, Jiang Nanxing, and gives her a black card with a ten-million limit, yet no funds can be withdrawn from it. For the sake of pride, Jiang Nanxing attends classes by day, carries cement by night, and even gives her last six thousand yuan to her adopted sister. Because of this, the sister confesses to her brother that the money on the card was swindled by the Zhao family, leaving a debt of three million. Unwilling to abandon her sister, Jiang Nanxing bursts into the Zhao family's clubhouse with evidence filmed while carrying cement, sternly rebuking the Zhao family: return every single cent of the money you cheated from my sister! This Beijing girl will stop at nothing to protect her sister.