When 28-year-old Su Wanrou was sorting through her mother's old belongings, she discovered a letter that Lu Yu wrote to her in high school but did not send. The letter contained the truth about their separation. At the same time, she met Lu Yu again at work, and the two were forced to intersect due to cooperation on two projects. The regrets of the past intertwined with the throbbing of the present, forcing her to face the choice of "whether to replenish her youth."
