Main Characters Kim Pil Sook Nana / Lee Jae Hee Si Woo Ailee Go Hye Mi Yoon Baek Hee Jason Shin Hye Sung Jin Yoo Jin Rian / Lee Ji Kyung Jin Gook / Hyun Shi Hyuk Jang Woo Jae
Recurring Guest Characters Jung Ha Myung 4 guest appearances Jin Gook's Roommate 3 guest appearances Kim Pil Sook 1 guest appearances Miss A 2 guest appearances Jo Soo Mi 1 guest appearances Kim Hyun Joong 1 guest appearances Ri Ah's CF Partner 1 guest appearances Oh Sun's Imaginary Boy 1 guest appearances Lee Teuk 1 guest appearances Eun Hyuk 1 guest appearances Baek Hee's Kirin Students 1 guest appearances Composing Teacher 1 guest appearances 16 year-old Hye Sung 1 guest appearances Kim Soo Hyun 1 guest appearances My Name 1 guest appearances Toxic 1 guest appearances Trainer Coach 1 guest appearances Park Ye Eun 1 guest appearances 2AM 1 guest appearances