With only one hundred days left until the Gaokao, senior high school student Yu Zihan repeatedly loses focus during class and is sternly reprimanded by his homeroom teacher. With the support of his teacher and close friends, he shakes off his lethargy and faces his academic struggles head-on. During the remaining hundred days, he settles down and devotes himself to studying, facing the eyes of those around him as he begins his own journey of youthful transformation between exam papers and his school desk.