In order to save his terminally-ill mother, Dong Cuican signs a "contract" with a mysterious man, trading his own time for his dying mother's life. After recovery, his mother Yan Jinyu returns to the age of 20 and is still healthy. By virtue of her maturity and optimism, she lives a more exciting life that she never expected. However, to not worry his mother, Dong Cuican conceals the truth about his life, and takes on the cost of the contract alone. He decides to make up for his regrets and repay his mother's love and care in his last days.