The Actors are :-

Ryu Hwayoung As Kim Yun Ji
-The beutiful girl and is liked by many guys.Ex girlfriend Shin Eun Min

Lee Hyuk Jae As Lee Hyuk Min
-A wise senior and he like at Kim Yun Ji

Lee Chang Sun As Kim Won Ho
-Hyuk Min's junior and he is a arrogant

Ham Eun Jung As Lee Jun Ji
-Junior who likes to bully Yun Ji and selfish

Nam Woo Hyun As Shin Eun Min
-Smart junior and Kim Yun Ji ex boyfriend

Extras :-

Park Jung Soo As Park Mun Ji
-Hyuk Min's friend

Bae Sue Ji As Min Sue Rim
-Yun Ji's friend

Park Ji Yeon As Shin Ji Mie
-Jun Ji's friend and Eun Min's sister

Jeon Bo Ram As Jim Min Heo
-Jun Ji & Ji Mie's friends

Lee Soo Kyung As Kim Ji Sue
-Kim Won Ho & Yun Ji's Mother