Top cast
Song Joong-ki
Wolf-Boy / Chul-soo
Park Bo-young
Young Sun-yi / Eun-ju
Yoo Yeon-seok
Ji-tae
Lee Young-ran
Sun-yi
Jang Young-nam
Sun-yi's Mother
Kim Hyang-gi
Sun-ja
Yoo Seung-mok
Professor Kang Tae-shik
Shin Bi
Dong-mi
Woo Jung-kook
Mr. Jung
Goo Bon-im
Mrs. Jung
Lee Jun-hyeok
Policeman
Soel Oh-shin
Thug 1 (uncredited)
