After a high school misunderstanding led them to miss each other, the pair returned to their alma mater as teachers following college graduation. Seven years passed before Muli Yang finally realized that the female physical education teacher, An Xun, was once the young girl he missed. However, things are different now; Yang is a kind yet conniving male math instructor, and Xun is unromantic and unfazed. As they reconnect, the past resurfaces, but they are not the same people anymore. Can they rekindle their relationship? And as the secrets of high school slowly reveal themselves, the truth behind their past may come to light.