Park Bo-young

Se-Hee

주원

Joon-Hyuk

강별

Jung-Mi

Kim Min-hyuk

Detective Kim

Lee Marg-Eum

girl

Kang Hae-In

cutie

Kwon Nam-hee

girl's mother

정동규

Se-Hee's father

Choi Ji-Hun

Ji-Hun

남경읍

Detective Jang

Min Young

homeroom teacher (uncredited)

Han Ye-Na

teacher (uncredited)

Kim Tae-kyung