Park Gun (Ryoo Ui-Hyun) has been a bullied student for the past 6 years at all the schools he went through. He transfers to Poongrang High School but realizes that the school is not a regular high school. The students of Poongrang High School are actually gang members attending school to get a high school diploma. The average age of the 3rd-grade students is 26. To survive at the school, Park Gun decides to flatter Park Tae-San (Kwak Min-Ho), the most powerful student at the school.