Kim Jung-eun as In-young

Lee Tae-sung as Lee Suk / Lee Soo

Kim Young-jae as Jung-woo

Jung Yu-mi as Young In-young

Lee Joo-sil as In-young's Mother

Kim Kkob-bi as Cram School Student

Jang So-yeon as ER Nurse

Choi Ban-ya as English Teacher

Jun Kim as Adult Lee Suk

Lee Seok as Young Jung-woo

Kwak Min-seok as Driver