Cast
Main Cast
Bae Suzy as Kelly Go (Go Hye Mi)
Kim Soo Hyun as Marco Song (Song Sam D**g)
Taecyeon as Gino (Jin G**k / Hyun Shi Hyuk)
Ham Eun Jung as Angelie Yoon (Yoon Baek Hee)
Wooyoung as Jason
IU as Gelou Kim (Kim Pil Suk)
Extended cast
Ahn Kil Kang as Ma Doo Shik
Ahn Sun Young as Kang Oh Sun (Oh Hyuk's older sister)
Ahn Seo Hyun as Go Hye Sung (Hye Mi's little sister)
Park Eun Bin as 16 ye
ar old Hye Sung (ep 16)
Lee Hye Sook as Song Nam Boon (Sam D**g's mother)
Choi Il Hwa as Hyun Moo Jin (Jin G**k's father)
Park Hyuk Kwon (박혁권) as Go Byung Jik (Hye Mi's father)
Park Hwi Soon as Jin G**k's roommate (ep 1,2,5)
Cameos
Jo Soo Mi (조수미) as herself (ep 1)
Kim Hyun Joong as himself (ep 1)
Nichkhun as Ri Ah's CF partner (ep 8)
Hwang Chan Sung as Oh Sun's imaginary boy (ep 12)
Lee Teuk as himself (ep 13)
Eun Hyuk as himself (ep 13)
Miss A as flash mob dancers (ep 16)
2AM as flash mob dancers (ep 16)
Dal Shabet as Baek Hee's Kirin students (ep 16)
Goo Joon Yup
Kirin's Teachers
Uhm Ki Joon as Kang Oh Hyuk
Lee Yoon Ji as Shi Kyung Jin
Park Jin Young (박진영) as Yang Jin Man (English teacher)
Lee Byung Joon as Shi Bum Soo (Principal)
Lee Yoon Mi as Maeng Seung Hee
Baek Won Kil (백원길) as Gong Min Chul
Bae Yong Joon as Jung Ha Myung (President) (ep 1-4)
Joo Young Hoon (주영훈) as composing teacher (ep 11)
Kirin's Students
Jun Ah Min as Jo In Sung (Jin G**k's friend)
Jung Min Joo (정민주) as Jung Ah Jung
Han Ji Hoo as Park Do Joon (sunbae)
Yoon Young Ah as Lee Ri Ah
Park Jin Sang (박진상) as Jun Tae San (sunbae)
Kim Bo Reum as Ha So Hyun (sunbae)
Bae Noo Ri (배누리)
