Song Ji-Hyo

Real Name          : Cheon Seong-im

Nickname            : Ace

                            : Blank Ji

                            : Monday Girlfriend

                            : Bad Ji-Hyo

                            : Gold Ji-Hyo

                            : Goddess of Luck

                            : Goddess of Sleep

Birthday               : 15 August 1981 (age 34 as of 2015)

Birthplace            : Pohang, North Gyeongsang, South Korea

Nationality          : South Korean

Years Active       : 2001-present

Occupation         : Actress, television personality

Cheon Seong-im, also known as Song Ji-Hyo, is a South Korean actress, television presenter, and model. She made her acting debut in Wishing Stairs (2003). Her notable roles include being the ballerina Min Hyo-rin in Princess Hours (2006), Lady Ye So-ya in Jumong (2007), The Queen in A Frozen Flower (2008), Jo Min Joo in Detectives in Trouble (2011), Hong Da In in The Fugitive of Joseon (2013), Oh Jin-Hee in Emergency Couple (2014) and Kim Soo-Jin in Ex-Girlfriend Club (2015). She gained international fame for being the only female member of the popular variety show Running Man.

On 29 December 2015, Song Ji Hyo appeared in Gary’s MV teaser for “Lonely Night” featuring Gaeko.

Song Ji hyo was originally a guest in Running Man but was added to the main cast in episode 6. During earlier episodes, Song Ji-hyo was know to swear during broadcasts, especially to Haha and Lee Kwang-soo, which earned her the nickname “Bad Ji-hyo”. She is also known to be often seen with confused or blank facial expressions a lot of time. Throughout the series, she has been involved in the official loveline of the show alongside Gary, known as ‘Monday Couple’ (because they are recording at Mondays). She is one of the strongest players in Running Man with similar running and catching capabilities as well as comparable intelligence to Yoo Jae-Suk and Kim Jong-Kook. 

source : wikipedia