Su Xiaoman, an ordinary but tenacious girl, was already overwhelmed by the burden of her family. Her mother was seriously ill and needed a huge amount of money for surgery, which put her in a desperate situation.
Gu Chengyu, the leader of the Yuncheng business giant Gu Group, is cold and ruthless and is known as the King of Hell in the business world. He and his girlfriend Lin Yan, who had been in love for many years, were about to get married, but Lin Yan ran away from the marriage on the eve of the wedding, which disgraced the Gu family.
In order to restore the dignity of the family, Gu Chengyu decided to find a substitute to complete the wedding. Because Su Xiaoman was somewhat similar to Lin Yan and needed money to save his mother, he had no choice but to sign a five-year contract to replace Lin Yan as Gu Chengyu's bride. On their wedding night, Gu Chengyu pinched her chin and warned her, pointing out that she was just a substitute and she had to imitate Lin Yan even when breathing.
Su Xiaoman hid the pregnancy test sheet and tried to play the perfect stand-in, but discovered a shocking secret in Gu Chengyu's study: in the fire twenty years ago, the girl who really saved him had a butterfly birthmark on her chest, and she had it herself.
With Lin Yan's return, the truth about Su Xiaoman's stand-in was revealed. He was also designed to be the leaker of the Gu Group's project, and was criticized by everyone. To make matters worse, Lin Yan was seriously ill, and Su Xiaoman's life was in danger due to a successful heart match and becoming the best transplant donor.
Gu Chengyu unknowingly fell in love with Su Xiaoman while getting along, but it was too late. When Su Xiaoman was lying on the operating table, he knelt in front of the operating room with red eyes and begged. Su Xiaoman smiled and pressed the anesthesia consent form to terminate the transaction early.
However, the gears of fate did not stop turning. Su Xiaoman's best friend brought a turn of events, and the world's top heart experts tried their best to rescue him.
