At Eighteen

Ong Seong-wu

Choi Joon-Woo· 16 ep

Kim Hyang-gi

Yoo Soo-Bin· 16 ep

Shin Seung-ho

Ma Whi-Young· 16 ep

Kang Ki-young

Oh Han-Kyeol· 16 ep

Shim Yi Young

Joon-Woo's mother· 16 ep

Kim Sun-young

Soo-Bin's mother· 16 ep

Choi Jae-woong

Choi Myeong-jun· 16 ep

Moon Bin

Jung Oh-je· 16 ep

Jeong Young-ju

Park Geum-ja· 16 ep

Jung Hyeon-jun

Choi Joon-Woo (young)· 16 ep

Yoo In-soo

Yoo Pil-Sang· 16 ep

Han Sung-min

Hwang Ro Mi [Soo Bin's classmate]· 16 ep

Kim Bo-yoon

Kwon Da-hwin· 16 ep

Moon Joo-yeon

Yoon So-ye· 16 ep

Baek Jae-woo

Go Dong· 16 ep

Kim Kwang-shik

[Oh Je's father]· 4 ep

Lee Do-hyun

[Sang Hoon's father]· 1 ep