Sehun

Koh You

Cho Jun-young

Koh Jun-hee

Jang Yeo-bin

Han So-yeon

Song Jae-rim

Dr. Koh

Eugene Jung

Han So-yeon (adult)

Lee Seung-joon

Koh You's father

Park Eun-hye

Koh You's mother

Jeong Hye-seon

Koh Jun-hee's grandmother

Jeon Young-in

An Sun-tak