Park Bo-young character Younger Sun-yi / Eun-ju
Song Joong-ki character Chul-Soo / Wolf-Boy
Lee Young-lan character Older Sun-yi
Jang Young-nam character Sun-yi's Mom
Yoo Yeon-seok character Ji-tae
Kim Hyang-gi character Sun-ja
Yoo Seung-mok character Professor Kang Tae-shik (uncredited)
Seo Dong-Soo character Army Colonel (uncredited)
Woo Jung-kook character Mr. Jung (uncredited)
Nam Jung-hee character Dong-suk's Grandmother (uncredited)
Goo Bon-im character Mrs. Jung (uncredited)
Ahn Do-Kyu character Dong-suk (uncredited)
Bi Shin character Dong-mi (uncredited)
Lee Jun-hyeok character Policeman 1 (uncredited)
Oh Yeong-seok character Policeman 2 (uncredited)
Kim Hae-eun character Woman Renting Mr. Jung's Room (uncredited)
Lee Min-woong character Dr. Kang's Assistant (uncredited)
Sung Du-hyung character Man in Black Suit 1 (uncredited)
Cha Jong-ho character Man in Black Suit 2 (uncredited)
Jung In-gum character (uncredited)
Kim Eun-sook character Military Chief (uncredited)
Kim Seung-hun character Public Official (uncredited)
Lee In-ho character (uncredited)
Lee Sung-ju character Sun-yi's son (uncredited)
Jang seo-yi character Sun-yi's Daughter-in-Law (uncredited)
Hung Hi-kwon character Hospital Doctor (uncredited)
Hong Sung-ki character Acupuncturist (uncredited)
Soel Oh-shin character Thug 1 (uncredited)
Han Min-hik character Thug 2 (uncredited)
Chuay Kwong-lak character Thug 3 (uncredited)
Jo Jae-yun character Sun-yi's Grandson (uncredited)
Ku Lu-han character (uncredited)
Kim Chul-jun character Construction Worker at Market 1 (uncredited)
Park Young-shik character Construction Worker at Market 2 (uncredited)
Kim Jong-goo character Sun-yi's Father (uncredited)
Shin Yeong-cheol character Eun-ju's Boyfriend (uncredited)
Koo Kyo-hwan character Drunk Man (uncredited)
