Choi Jihoon is assigned to Daehun High School, the worst high school in Korea. He pledges to be the ‘Jjang (Top gangster)’ here, but the reality is quite tough.

"Jeongman," tired of the same daily life every day, comes up with a part-time idea of "human sandbag" that exchanges money for a mill while trying to make money. From that day on, the feisty guy "Hwi" and the strongest millhouse "Minkyu" become a team and go up the road with only one glove in their hands. However, the deviation is brief, money and instincts are not easily satisfied, and the thirst of blood-sheding fighters is deepening. One day, the mysterious alumni "Yoo Young," who appeared in front of them, made an unconventional offer to make three times the profit, and they entered the secretly operated martial arts gambling board.