In order to save his terminally ill mother, the unfilial son Dong Cuican signed a "contract" with a mysterious man, exchanging his own time for his dying mother. After recovery, his mother Yan Jinyu not only returned to her healthy state at the age of 20, but also relied on her maturity and optimism that surpassed her "peers" to live a more wonderful life that she had never dared to imagine. However, on the other hand, in order not to worry his mother, Dong Cuican concealed the truth about his life and shouldered the cost of the contract alone. And decided to make up for his past regrets and repay his mother's kindness in the last time of his life...