소지섭

Woo-jin

손예진

Soo-a

Kim Ji-hwan

Young Ji-ho

고창석

Hong-gu

이준혁

Swimming Instructor

손여은

Hyun-jung

이유진

Young Woo-jin

김현수

Young Soo-a

배유람

Young Hong-goo

서정연

Seo-bin's Mother

박서준

Ji-ho

공효진

Han Bok-nyeo

Lee Min-sung

Seo-bin

이승준

PE Teacher

Shin Woo-hee

Homeroom Teacher

조하석

Relative

Seo Young-sam

Bus Driver

정수빈

So-jung

백현우

Math Teacher in the Past

정서인

Relative