Kwak Dong-yeon

as Choi Jung Woo

4 episodes

Lee Se-young

as Yang Ah Young

4 episodes

Kwak Jung-wook

as Im Duk Won

4 episodes

Choi Tae-joon

as Lee Yuk Ho

4 episodes

Park Jeong-min

as Shin Young Bok

4 episodes

Bae Noo-ri

as Jang Hyun Jin

4 episodes

Yoon Park

as Lee Won Il

4 episodes

Baek Sung-hyun

as adult Choi Jung Woo

4 episodes

Jeong In-gi

as Jung Woo's father

4 episodes

Koh Soo-hee

as Jung Woo's mother

4 episodes

Oh Youn-hong

as Ah Young's mother

4 episodes

Jeong Soo-young

as Homeroom Teacher

4 episodes

Yun Ju-sang

as Yuk Ho's grandpa

4 episodes

Ahn Ji-hyun

as Moon Soo Jung

4 episodes

Kim Dong-hee

as Park Sung Tae

4 episodes