Kadro (15)
SehunKoh You
Cho Jun-youngKoh Jun-hee
Jang Yeo-binHan So-yeon
Song Jae-rimDr. Koh
Jung Yoo-jinHan So-yeon (adult)
Lee Seung-joonKoh You's father
Park Eun-hyeKoh You's mother
Jeong Hye-seonKoh Jun-hee's grandmother
Jeon Young-inAn Sun-tak
Baek Min-hyunAn Sun-tak (adult)
Kwon Hyeok-beomJeon Sang-kyu
Lee AraShim Jung-eun
Seo Beom-sikTeacher
Myung Jae-hwanHomeroom Teacher
Kim Kyung-namMan at the Park