Lin Xi, a fresh graduate, rented a one-bedroom apartment in an old city. When moving, she found a stack of unsent letters deep in the closet. The writer was Xia He, a girl who lived here ten years ago, and the recipient was her first love. Lin Xi followed the clues in the letter and pieced together Xia He's youth story bit by bit: passionate love, helpless separation, and regretful miss. At the same time, Lin Xi met her neighbor Chen Yu at work, and the two became familiar with each other because they took care of the stray cats downstairs. Chen Yu's gentleness cured Lin Xi's workplace anxiety, and Lin Xi also helped Chen Yu get out of the shadow of broken love. As the seasons passed, Lin Xi not only sent Xia He a letter that was ten years late, but also gained his own warmth. It turns out that all the regrets were for meeting a better person.
