Seventeen-year-old Lin Wei fell in love at first sight with transfer student Jiang Yi in the morning light of the second semester of high school. Her youth has since become a long secret love, like a secret diary hidden in the desk, filled with unspoken thoughts, silent pursuits and restrained concessions. From secretly watching from the back window of the classroom, to stopping by the basketball court pretending to be passing by, to the torn confession letter during the graduation season, she tasted the sourness and pain of secret love in this alone war, and finally said goodbye to that dazzling boy and her immature self quietly in the chirping of cicadas at the end of summer.