is a South Korean actress, singer, author and director. An admirer of Leonardo Da Vinci, Ku also dabbles in directing, writing, illustrating, singing and composing. She is best known for her role as Geum Jan Di in the hit TV show Boys Over Flowers.

Ku entered the entertainment industry after gaining popularity on the internet as an ulzzang. She began her acting career in one-act dramas and the sitcom Nonstop 5. She was also co-MC with Heechul of Super Junior on SBS's weekly live music show Inkigayo from April 23, 2006 to February 18, 2007. Ku soon rose to fame in the drama Pure in Heart and surprised critics with her performance in the historical drama The King and I. She is most well known for portraying Geum Jan-di in the hit KBS drama Boys Over Flowers. After a year in limbo with no broadcasting slot, [5][6] her pre-produced drama The Musical finally aired in September 2011.[7][8][9] Ku next starred as a female pilot in the SBS series Take Care of Us, Captain, [10][11][12] followed by the Taiwanese drama adaptation of the manga Absolute Boyfriend.[13][14] Originally set to debut as a singer (supposedly in a 3-member girl group with 2NE1's Park Bom and Sandara Park), YG Entertainment CEO Yang Hyun-seok advised Ku to pursue acting rather than music. In recent years, she has displayed her vocal talents through Saranga (which became the title song of Pure in Heart), a cover of Shim Soo-bong's I Don't Know Anything But Love (which played during a crucial scene in Boys Over Flowers), and a duet of Kim Gun Mo's song Rain Falls on a Sleepless Night with Big Bang member Seungri on the music talk show Lee Hana's Peppermint. Ku has also composed an album of New Age music titled Breath.

Ku wrote Tango, a semi-autobiographical novel about a twenty-something woman's experience with love and relationships. The book was a bestseller, selling 30, 000 copies within a week. Its release coincided with her first solo art exhibition, also titled Tango, in July 2009 at La Mer Gallery, which attracted 10, 000 visitors. The exhibition featured around 40 of Ku's illustrations, some from her novel.[15][16][17] She has also done artwork for Gummy's fourth album Comfort.

Ku made her official debut as a director through her short film The Madonna (Korean title translates to The Cheerful Caretaker) at the 2009 Puchon International Fantastic Film Festival.[18][19][20] In 2010 she wrote and directed her first feature-length film Magic, [21] followed by more short films and trailers.

Director and actress Goo Hye Sun has become a freshman at Sungkyunkwan University for the 2011 school year. She will be attending the school next March as an arts major. In an interview with MyDaily on October 29th, Goo Hye Sun revealed, “I’m extremely glad to be able to enter college.” Goo Hye Sun previously attended Seoul Institute of the Art but was forced to give up her education due to her busy schedule. She continued, “I wanted to continue studying, which is why I submitted an application privately in order to achieve my dream.” She went on to talk about her interests in directing as well, stating, “I hope to study directing a bit more and a variety of other areas as well.” Her self directed movie, “Magic, ” was invited to the Tokyo Film Festival on October 27th.

In 2011 Ku established her own company, Ku Hye-sun Film, under which she will produce and film her projects, which offers her a measure of legal/business protection.[22] Her second directorial feature The Peach Tree was the first film made by her newly established production company.[23][24][25] She said of directing, "It’s tiring and grueling. At times you ask yourself, 'Why am I doing this?' But movies have the ability to make you feel alive."[26]

Я могу вытерпеть голод. И с холодом могу справиться. Но есть одно, чего я не могу вынести. Страдания близких людей по моей вине

— Почему ты никогда не говоришь, что я тебе нравлюсь?
— А тебе нужно услышать, чтобы поверить?