Shim Kyu-hyuck

Park Hyung Seok (Small) (voice)

Han Shin

Park Hyung Seok (Big) (voice)

Ryu Seung-gone

Lee Jin Seong / Park Jong Gun (voice)

Jeong Jae-heon

Vasco / CEO / Lee Nam Su (voice)

Hwang Chang-yung

Pyun Deok Hwa / Lee Tae Sung / Oira (voice)

Sa Moon-young

Park Ha Neul / Female Student / Female Extra (voice)

Kim Hyeon-uk

Lee Hyun Do / Go Jeong Gi / Kim Seul Bum (voice)

Lee Gyu-chang

Na Yu Eop / Park Han Gyul / Homeroom Teacher (voice)

Bae Jeong-mi

Choi Soo Jeong / Deok Hwa's Grandmother / Female Student (voice)