Episode 1 S01E01

Kim Hyeon-soo

Ko Seo-Yeon

Jang Dong-yoon

Han Ji-Hoon

Seo Ji-hoon

Bae Joon-Young

Seo Young-joo

Lee So-Woo

Seo Shin-ae

Park Cho-Rong

Cho Jae-hyun

Han Kyung-Moon

Shin Se-hwi

Lee Joo-Ri

Ahn Seung-gyun

Choi Seung-hyeon

Ahn Nae-sang

Ko Sang-Joong

Kim Yeo-jin

Seo-Yeon's mother

Shin Eun-jung

Teacher Kim

Yoo Ha-bok

Principal

Shim Yi Young

Detective Oh

Ahn Sol-bin

Lee Yoo-Jin

Ji E-su

homeroom teacher

Lee Do-gyeom

Lee Sung-Min