Still 17

Yang Se-jong

Gong Woo-Jin

Shin Hye-sun

Woo Seo-Ri

Ahn Hyo-seop

Yoo Chan

Ye Ji-won

Jennifer

왕지원

Kim Tae-Rin

Eugene Jung

Kang Hee-Soo

윤선우

Kim Hyeong-Tae

시은

Woo Seo-Ri (young)

Yoon Chan-young

Gong Woo-Jin (young)

Ahn Seung-gyun

Jin-hyun

조현식

Han Duk-soo

Lee Do-hyun

Dong Hae-Beom

Kim Min-Seo

Im Byeong-gi

Gong Yong Hwan [Gong Woo Jin's father]

Park Hyun Jung

Kim Tae-rin's Mother