Han-cheol and his buddies, Geon-mo and Min-ho, want to be the dominators of 11th grade. He gets rid of likely candidates of the 11th grade one by one. One of his opponents is Sang-gil and after school one day, they decide to fight behind an alley. The fight ends with the police appearing, and while the result is inconclusive, they each realize how good their opponent is.

The school finds peace with Han-cheol's dropping out. Min-soo, whose fighting abilities have intensified, bluffs his friends. Sang-gil discovers that the number of students in the school's secretly run fight club is increasing and asks Yoon-hyeok who the prime leader of the club is. Yoon-hyeok tells him it is Min-soo and Jin-man. Jin-man and Min-soo are wrongly accused and sought for the fight club, when Yeon-ji, who abandoned them, returns. They reject her, but end up being in a good relationship with her again. Then they run into Ga-yeong and sneak into a fight club meeting...

In the middle of peaceful days as two top leaders, tender-hearted Jin-man and his friend Min-soo, though both martial arts school legends, felt a new thrill after a mysterious schoolgirl, Soo-jeong, visits their boxing club. Meanwhile, unidentified Japanese high school students begin to raise suspicions in Seoul. The former Japanese yakuza's son, Miura, and the hidden daughter of the Japanese prime minister and center of the nation's far-right forces, Miyo, stirs up a fight between Korea and Japan to determine who is the strongest. Korea vs. Japan! May the last baddest guy survive!

Han-cheol, along with his gang, Geon-mo and Min-ho, tries to be the best in second grade. One by one, they beat out the talented second year students as if beating dojo masters. Han-cheol learns about a master, Jin-man, through a video. Without any idea what is going on, Min-su, wanting to practice finds a boxing ring where Jin-man also practices, and so begins to sleep with the two enemies. However, they need each other so they avoid their uncomfortable jealousies.