Countdown

Jin Sun-kyu

Si-heon

Sung Yoo-bin

Yoon-woo

Oh Na-ra

Il-sun

Ko Chang-seok

Principal

Jang Dong-ju

Hwan-ju

Ko Kyu-pil

Man-deok

Kim Min-ho

Bok-an

Lee Jong-hwa

Gao

Choi Hyung-tae

Bok-co

Cho Jung-hun

Jody

Tae In-ho

Song Hee-cheol

Cha Soon-bae

President

Lee Jun-hyeok

Reporter

Lee Hong-nae

Lee Dong-su

Woo Yeon-seo

Teacher Park

Woo Jeong-won

Yoon-woo's mother