Dong-ho is ranked number 1 in "Arena," an illegal gambling league for teens, but he steps down to prepare for college. However, the members of "Arena" don't want to lose their biggest money-maker, so they place a debt on his brother Dong-min. Dong-min literally fights against his debt, but when he gets hurt, Dong-ho decides to fight back.

• Kim Do-gun
• Yoon Kyung-ho
• Wang Woo-jin
• Seo Seung-hyun
• Kim Si-yu
• Kim Dae-han
• Bang Sang-hyun
• Jang Yong-hee