During the summer of his junior year in high school, Woo-Yeon (Kim Young-Kwang) isn't interested in studying and spends his time getting into fights. He then meets new transfer student Seung-Hee (Park Bo-Young) and falls in love with her at first sight. But, Seung-Hee isn't interested in Woo-Yeon. To avoid the other male students, Seung-Hee and Woo-Yeon pretend to date, and Seung-Hee asks him to stop fighting. He keeps his promise and their friendship develops into a real romantic relationship.