Sim Hee-seop

Dong-jun

홍사빈

Young Dong-jun

Shin Joo-hyup

Young Kang-hyeon

김소희

Young Dong-hee

Kang Chae-yun

Yeong-ji 1

Ju-Ryoung Kim

Dong-jun's Mother

Kim Hak-sun

Dong-jun's Father

권지우

Ju-ho

옥지영

Yun-ju

권동호

Seong-il

송창의

Kang-hyeon

우미화

Academy director

곽정길

Elderly Man in Room 502

안민영

Dong-jun's Stepmother

손지나

Kang-hyeon's Mother

Son Seong-chan

Kang-hyeon's Father