Dong Cui Can trades his remaining years to save his mother's life, and the show understands that this isn't a heroic gesture, it's a debt he's finally paying. When she comes back as her 20-year-old self, the impossible happens: mother and son have to learn who they are to each other outside of sacrifice and obligation. The show moves between comedy and something quieter, a son watching his mother actually live instead of just survive, both of them running out of time in different ways.

Dong Cui Can's mother is terminally ill, and to save her he makes a deal with a mysterious stranger, trading his own remaining years for hers. The stranger does more than heal her: Yan Jin Yu comes back as her 20-year-old self and becomes a college student with a whole life ahead of her. Drawing on a maturity and optimism beyond her new peers, she sets out to live more fully than she ever dared to imagine. Cui Can, once an unfilial son, keeps the true cost of the contract hidden so she won't worry. He resolves to spend his last days making up for past regrets and repaying her for the sacrifices she made raising him. Things get complicated when one of his friends falls in love with her. The show mixes comedy, drama and slice of life across 18 episodes.