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)

Nam Doh-hyeong
Jin Ho Bin / Jang Gi Seok / Kim Mae Sik / Park Bum Jae (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)