
Casts

Song Joong-ki
as Wolf-Boy / Chul-soo

Park Bo-young
as Young Sun-yi / Eun-ju

Yoo Yeon-seok
as Ji-tae

Lee Young-ran
as Sun-yi

Jang Young-nam
as Sun-yi's Mother

Kim Hyang-gi
as Sun-ja

Yoo Seung-mok
as Professor Kang Tae-shik

Shin Bi
as Dong-mi

Woo Jung-kook
as Mr. Jung

Lee Jun-hyeok
as Policeman