Ying'er has never seen the emperor or even a member of the royal family since she was born, but everything changed on her thirteenth birthday. It turns out that she is the Prime Minister's daughter, but she was swapped by her nanny when she was born, and her own daughter was replaced by the Prime Minister's daughter. Although the nanny was kind to her since she was a child, the gears of fate seemed to be turning rapidly from the moment she was swapped...