Set in a rural town in 1982, Young-sook (Park Bo-young) is the feared leader of a female gang at Hongseong Agricultural High School. Although she is known for her toughness and foul mouth, she secretly has a crush on Joong-gil (Lee Jong-suk), the biggest playboy in school. Joong-gil is a legendary Casanova whose single glance has the ability to make girls' hearts melt, and he's attempted to woo all the girls at school, except for Young-sook. That's because Gwang-sik (Kim Young-kwang (actor)), the leader of a rival school's male gang, views Young-sook as his girl.