W.H.Y. : What Happened to Your relationship

Jung Gun-joo

as

Cha Yeon-wu

Oh Ah-yeon

as

Song Da-in

Yoo Dong-guk

as

Oh Seul-gi

Hwang In-yeop

as

Gi Jae-young

Lee Ji-won

as

Lee Han-na

Lee So-hee

as

Yeo Ju-hyun

Kim Young-jae

as

[Dain's ex-boy...

Choi Hee Seung

as

Kim Min Woo (E...

Im Hwe Jin

as

Kwak Jun Mo (E...