Kwon Sang-woo as Hyeon-su

Lee Jung-jin as Woo-shik

Han Ga-in as Eun-ju

Lee Jong-hyuk as Cha Jong-hoon

Park Hyo-joon as Ham Jae-bok

Seo Dong-won as Seong-hun

Kim Dong-young as Young Hyeon-su

Cho Jin-woong as Yasaengma Gang Member

Lee Gyu-ho as Yasaengma Gang Leader

Kim In-kwon as Jiksae

Baek Bong-ki as Cheetah

Ahn Nae-sang as Teacher

Kim Byung-choon as Choi Byeong-sam

Kwon Tae-won as English Teacher

Cheon Ho-jin as Hyeon-su's Father

Lee Hyeon-seok as Hyun-soo's Mother

Jun Sung-ae as Jong-hoon's Mother

Yang Han-seok as P.E. Teacher

Park Soo-young as Politics & Economics Teacher

Kim Bu-seon as Boniface

Lee Jang-woo as Student

Baek Joo-hee as Student

Lee Gun-moon as Korean crow-tit's gang