Jung Jae-young
— Kim Sang-nam
Yu Seon
— Na Joo-won
Kang Shin-il
— Vice Principal
장기범
— Cha Myeong-jae
김혜성
— Jang Dae-geun
조진웅
— Charles
Kim Mi-kyeong
— Principal Nun
Lee Hyun-woo
— Kim Jin-man
지일주
— Oh Chul-jin (uncredited)
김동영
— Jo Jang-hyuk (uncredited)
Son Seung-won
— Park Choong-nam (uncredited)
김호원
— Goon San High Baseball Team
Chan-Hyeong Jo
— Choong Joo Sung Sim School Baseball Team, Lee Cheol-Seung