A new transfer student, Lin Xiangzhi (Zhao Jinmai), who is quiet and intelligent but always alone, does not make friends with the other students. However, she attracts the attention of Xu Youshu (Lin Yi), a scum of the class. In the process of trying to befriend Lin Xiangzhi, he, the eccentric Song Xiaonan (Shen Yue) and the cool-headed Jiang Wu (Wang Jiahui) discover Lin Xiangzhi's secret, that she suffers from a special disease and her memory of her friends is only seven days.