Lee Soo-kyung as Yong-soon

Choi Deok-moon as Father

Park Keun-rok as PE Teacher

Kim Dong-young as Bbak-gyu

Jang Hat-sal as Moon-hee

Choi Chan-sook as Che-yook's Mother

Kim Ja-young as Moon-hee's Mother

Park Chul-min as Chief of School Administration

Kim Min-jae as Music Teacher

Choi Yeo-jin as English Teacher

Kim Eung-soo as Principal

Kim Han-na as Athletic Club Senior

Kim Ha-yeon as Young Yong-soon

Kim Young-jae as Birth Mother's Old Love

Lee Na-ra as Birth Mother

Park Ji-yeon as Art Teacher

Jang Hye-jin as Middle-aged Woman

Kim Keum-soon as Supermarket Worker

Na Ae-jin as Athletic Club Member

Han Sa-myeong as New Gym Teacher

Woo Yeon-seo as Ethics Teacher