Jiang Xiaojin loves persimmons, so there's always one in the side pocket of A Cheng's backpack, ready for him to give her whenever she gets hungry.
Later, A Cheng fills the yard with persimmon trees, just so she'd think of Jiang Xiaojin when she picked the fruit in autumn. Later still, A Cheng keeps a persimmon in his side pocket, but the fruit tastes different, and he gives it to someone else.
Xu Cheng knows she won't turn back this time. The truth is, she never really moved forward; she just won't go back anymore. A Cheng doesn't want to have regrets about their youth, either. It's just that, when necessary, she has to learn to let go of the people who matter to her.
Theme: Growing up