Ji Yinsheng (Song Seung-heon) is a high school student in Shanggao. He is handsome and has a bad temper. He is one of the four famous kings in Shanggao. He is famous in the surrounding high schools, especially the girls' high schools. Han Qiansui (Jung Dabin) is an ordinary female high school student. She looks ordinary, but she is kind, lovely and full of energy. School is about to start. Qiansui is wandering on the Internet. She accidentally saw a provocation to all classmates signed by "Ji Yinsheng" on the school message board. Qiansui fought back mercilessly. Then she received a threatening call from Ji Yinsheng and inexplicably became his girlfriend. In her relationship with Ji Yinsheng, Qiansui slowly understood his fragile inner world under his unruly appearance, his desire for affection and his loyalty to friends, and there was a real relationship between the two.