* Goo Hye Sun as Geum Jan Di

F4:

* Lee Min Ho as Goo Joon Pyo
* Kim Hyun Joong as Yoon Ji Hoo
* Kim Bum as So Yi Jung
* Kim Joon as Song Woo Bin

Extended Cast

* Kim So Eun as Chu Ga Eul (Jan Di’s best friend)
* Kim Hyun Joo as Goo Joon Hee (Joon Pyo’s elder sister)
* Lee Hye Young as Kang Hee Soo (Joon Pyo’s mother)
* Ahn Suk Hwan as Geum Il Bong (Jan Di’s father)
* Im Ye Jin as Na Gong Joo (Jan Di’s mother)
* Park Ji Bin as Geum Kang San (Jan Di’s younger brother)
* Han Chae Young as Min Seo Hyun (F4′s best friend/Ji Hoo’s ex girl friend)
* Lee Min Jung as Ha Jae Kyung (JK Group’s CEO’s daughter and Jun Pyo’s fiancee)
* Lee Jung Gil as Yoon Seok Young (Ji Hoo’s grandfather)
* Jung Ho Bin as Jung Sang Rok (Kang Hee Soo’s Chief Secretary)
* Lee Si Young as Oh Min Ji
* Gook Ji Yun as Choi Jin Hee / Ginger
* Jang Ja Yun as Park Sun Ja / Sunny
* Min Young Won as Lee Mi Sook / Miranda
* Kim Ki Bang as Bom Chun Sik (Jan Di and Ga Eul’s boss)
* Song Suk Ho as Butler Lee
* Kim Young Ok as Head Maid
* Im Ju Hwan as So Il Hyun (Yi Jung’s older brother)
* Park Soo Jin as Cha Eun Jae (Yi Jung’s first love)
* Kim Min Ji as Jang Yoo Mi
* Kim Jong Jin as So Hyun Sub (Yi Jung’s father)
* Jung Ui Chul as Lee Min Ha / Min Jae Ha (fashion model)
* Kim Hyung Joon as himself (cameo, ep4)
* Kim Kyu Jong as himself (cameo, ep4)
* Heo Young Saeng as himself (cameo, ep4)
* Lee Hae Woo as Host Q (the guy who drugged Jan Di’s drink, ep4)
* Lee Jung Joon as Gong Soo Pyo (Ga Eul’s boyfriend, ep9-10)
* Heo Kyung Hwan as (Cell phone event MC, ep10)
* Lee Jung Sung as radiologist (cameo, ep13)
* Hai Ming (하이밍 ) as Ming (Ji Hoo’s friend, ep14-15)
* Lee Suk Goo (이석구 ) as (Shinhwa’s high school principal)
* Jo Soo Bin as announcer
* ?? as Goo Bon Hyung (Joon Pyo’s father)