Question: When was the South Korean singer, actor, host and entertainer born who was known as Ballad Prince and was also a star of Gu Family Book?

full_context: Document 1: Lee Min-ho (actor, born 1987): Lee Min-ho (, born June 22, 1987) is a South Korean actor and singer. He first gained widespread fame in Korea and parts of Asia with his role as Gu Jun-pyo in "Boys Over Flowers" in 2009. The role won him a Best New Actor award at the 45th Baeksang Arts Awards. He is noted for his leading roles in "City Hunter" (2011), "The Heirs" (2013) and "The Legend of the Blue Sea" (2016). The success of Lee's television dramas throughout Asia established him as a top Hallyu star. Lee starred in his first leading role in film with "Gangnam Blues" (2015), followed by his first China-produced film "Bounty Hunters" (2016).
Document 2: Kang Seung-yoon: Kang Seung-yoon (born (1994--) 21, 1994 ), known as Seungyoon, is a South Korean singer-songwriter, record producer, actor, and leader of boy group Winner. In 2010, he participated in the reality television singing contest "Superstar K2" and finished in fourth place. In January 2011, he became a trainee under YG Entertainment and went on to debut as a solo artist in July 2013 and as the leader of Winner in October 2013.
Document 3: The Legend of the Blue Sea: The Legend of the Blue Sea () is a 2016-2017 South Korean television series starring Jun Ji-hyun and Lee Min-ho. Inspired by a classic Joseon legend from Korea's first collection of unofficial historical tales about a fisherman who captures and releases a mermaid, this drama tells the love story of a con-artist and a mermaid who travels across the ocean to find him. It aired on SBS every Wednesday and Thursday at 22:00 (KST) started from 16 November 2016 until 25 January 2017.
Document 4: Gu Family Book: Gu Family Book (; also known as Kang Chi, the Beginning) is a 2013 South Korean television series starring Lee Seung-gi and Bae Suzy. The fusion martial arts action historical drama is about a half man-half monster who is searching for a centuries-old book that according to gumiho legend, contains the secret to becoming human.
Document 5: Invincible Lee Pyung Kang: Invincible Lee Pyung Kang (), also known as Taming of the Heir, is a 2009 South Korean television series starring Nam Sang-mi and Ji Hyun-woo. In a modern retelling of the classic Korean folktale "Princess Pyeonggang and the Fool Ondal" in which a princess helps her timid husband transform into an outstanding general during the Three Kingdoms era, Lee Pyung-kang is a golf course planner who "tames" Woo On-dal, the prodigal son of a rich man. It aired on KBS2 from November 9 to December 29, 2009 on Mondays and Tuesdays at 21:55 for 16 episodes.
Document 6: Lee Joon-gi: Lee Joon-gi (born 17 April 1982) is a South Korean actor, singer and model. He rose to fame on his first leading role playing a clown in the film "The King and the Clown" (2005) and the television series "My Girl" (2005). Since then, he has starred in television series "Iljimae" (2008), "Arang and the Magistrate" (2012) "Scholar Who Walks The Night" (2015) and "" (2016).
Document 7: Lee Gi-kwang: Lee Gi-kwang (Korean: 이기광 ; born March 30, 1990), known professionally as Gikwang or Kikwang, is a South Korean singer-songwriter and actor. He originally debuted as solo singer with the stage name AJ (Ace Junior), releasing his first mini album "First Episode: A New Hero" on April 4, 2009. In October 2009, he debuted as the main dancer, visual and a lead vocalist of boy group BEAST which had been renamed to Highlight in February 2017.
Document 8: Seungri: Lee Seung-hyun (Hangul: 이승현; born December 12, 1990), better known by his stage name Seungri (Hangul: 승리, "Victory") and V.I when performing in Japan, is a South Korean singer, songwriter, record producer, actor, and entrepreneur. In the mid-2000s, Seungri rose to prominence as one of three vocalists and youngest member of the South Korean boy band Big Bang under YG Entertainment, which eventually became one of the best-selling digital group of all-time in Asia and one of the best-selling boy bands in the world. With the release of the group's second studio album "Remember" (2008), in which the second single released, "Strong Baby", was performed solely by Seungri, he began to adopt a more mature image as an artist.
Document 9: Hwayi: A Monster Boy: Hwayi: A Monster Boy () is a 2013 South Korean action thriller film about a 16-year-old boy of the same name (played by Yeo Jin-goo) who is raised by five criminal fathers to become the perfect assassin. It takes pulling the trigger to discover his true identity after he realizes the mystery surrounding his past and his fate. It was the highly anticipated second feature film by director Jang Joon-hwan, a decade after his 2003 cult favorite sci-fi comedy/thriller "Save the Green Planet!".
Document 10: Lee Seung-gi: Lee Seung-gi (Hangul: 이승기 ; Hanja: 李昇基 ; born January 13, 1987) is a South Korean singer, actor, host and entertainer. Known as the "Ballad Prince", Lee has had numerous hit songs such as "Because You're My Woman", "Will You Marry Me", and "Return". He has garnered further recognition as an actor with leading roles in popular dramas such as "Brilliant Legacy" (2009), "My Girlfriend Is a Nine-Tailed Fox" (2010), and "Gu Family Book" (2013). He was a member of the first season of weekend variety show "1 Night 2 Days" from November 2007 to February 2012, and the host of talk show "Strong Heart" from October 2009 to April 2012.
Document 11: Love in the Moonlight: Love in the Moonlight () is a South Korean television series starring Park Bo-gum and Kim Yoo-jung with Jinyoung, Chae Soo-bin and Kwak Dong-yeon. It is a coming-of-age story and youth romance set during 19th-century Joseon Dynasty based on the novel "" which was first serialized on Naver in 2013 and consequently published as a five-part series of books in 2015. It aired every Monday and Tuesday from August 22, 2016 until October 18, 2016 on KBS2 at 22:00 (KST) for 18 episodes.
Document 12: Guardian: The Lonely and Great God: Guardian: The Lonely and Great God (), known internationally as simply Goblin, is a South Korean television series starring Gong Yoo, Kim Go-eun, Lee Dong-wook, Yoo In-na, and Yook Sung-jae. It aired on cable network tvN every Friday and Saturday at 20:00 starting December 2, 2016 until January 21, 2017.
Document 13: Kim Hee-chul: Kim Hee-chul (born July 10, 1983), better known by the mononym Heechul, is a South Korean singer, songwriter, presenter, and actor. He is a member of South Korean boy group Super Junior and has further participated in its subgroup, Super Junior-T as well as project group with TRAX's Jungmo, M&D. Aside from group activities, he participated in various television dramas, appeared as a radio DJ and television presenter. He is a "League of Legends" Gamer on LoL "Champions" and "Celebrity Event".
Document 14: A Werewolf Boy: A Werewolf Boy (; lit. "Wolf Boy") is a 2012 South Korean fantasy romance film in which a beautiful teenage girl (Park Bo-young) is sent to a country house for her health, where she befriends and attempts to civilize a feral boy (Song Joong-ki) she discovers on the grounds — but the beast inside him is constantly waiting to burst out.
Document 15: Kim Jong-hyun (singer): Kim Jong-hyun (born April 8, 1990), better known by the mononym Jonghyun, is a South Korean singer-songwriter, and radio host. He is a vocalist of the South Korean boy group Shinee, and has further participated in S.M. Entertainment's project group S.M. The Ballad. Jonghyun debuted as a solo artist on January 12, 2015, with his first EP, titled "Base". In the same year, on September 17, Jonghyun released a compilation album, "Story Op.1". On May 24, 2016, Jonghyun released his first studio album, "She Is", followed by his second compilation album, "Story Op.2" on April 24, 2017.
ground_truth: January 13, 1987