Question: Who directed the 2011 South Korean courtroom thriller film that starred actress Kim Sung-ryung?

Context paragraphs:
Kim Sung-ryung: Kim Sung-ryung (born February 8, 1967) is a South Korean actress.  After winning the Miss Korea beauty pageant in 1988 (she later represented her country at the Miss Universe 1989 pageant), Kim began her career as a reporter on KBS's showbiz news program "".  In 1991, she made a memorable film acting debut in Kang Woo-suk's "Who Saw the Dragon's Claws?" , though she became more active in television in the next decade.  She returned to the big screen in 2007, with notable supporting roles in "Shadows in the Palace", and "Rainbow Eyes", followed by "The Client" (2011), "Mr. XXX-Kisser" (2012), "The Fatal Encounter" (2014), and "The Target" (2014).  As she entered her forties, Kim also became known for the television dramas "You're Beautiful" (2009), "The Chaser" (2012), "Yawang" (2013), "The Heirs" (2013), and "Queen's Flower" (2015).

My World Only: My World Only is an upcoming South Korean drama film directed by Choi Sung-hyun.  The film stars Lee Byung-hun, Youn Yuh-jung, Park Jung-min, Han Ji-min and Kim Sung-ryung.

How to Meet a Perfect Neighbor: How to Meet a Perfect Neighbor () is a 2007 South Korean television series starring Kim Seung-woo, Bae Doona, Park Si-hoo, Wang Ji-hye, Son Hyun-joo and Kim Sung-ryung.  It aired on SBS from July 25 to September 27, 2007 on Wednesdays and Thursdays at 21:55 for 20 episodes.

Kim Sung-kyung: Kim Sung-kyung (born February 15, 1972) is a South Korean television personality and actress.  Kim joined the broadcasting network SBS in 1993 as a news presenter, notably as the weekend anchor for the "SBS Eight O'Clock News".  She left SBS in 2002 to go freelance, and also became a planning director for the "edutainment" company SangSang and I in 2007.  Kim made her acting debut in 2014 (her older sister is actress Kim Sung-ryung), and has appeared in Korean dramas such as "City of the Sun" (2015).

Definitely Neighbors: Definitely Neighbors (; also known as "Neighbor Enemies") is a 2010 South Korean television drama starring Son Hyun-joo, Yoo Ho-jeong, Kim Sung-ryung and Shin Sung-rok.  It aired on SBS from March 13 to October 31, 2010 on Saturdays and Sundays at 20:50 for 65 episodes.

King of Ambition: King of Ambition () is a 2013 South Korean television series, starring Kwon Sang-woo, Soo Ae, Jung Yun-ho, Kim Sung-ryung, and Go Joon-hee.  It aired on SBS from 14 January – 2 April 2013 on Mondays and Tuesdays at 21:55 for 24 episodes.  Based on Park In-kwon's manhwa of the same title, the same source material as "Daemul", the drama tells the tale of an ambitious woman born into poverty who will let nothing stand in her way as she tries to become the First Lady, and a hopeless romantic who will sacrifice anything for her.  But when she betrays him, he takes his revenge.

Mrs. Cop 2: Mrs. Cop 2 () is a 2016 South Korean drama series starring Kim Sung-ryung and Kim Min-jong.

The Target (film): The Target () is a 2014 South Korean action-thriller film starring Ryu Seung-ryong, Lee Jin-wook, Yoo Jun-sang and Kim Sung-ryung, and directed by Yoon Hong-seung (who also goes by the pseudonym Chang).  It is a remake of the 2010 French film "Point Blank".

The Client (2011 film): The Client () is a 2011 South Korean courtroom thriller film director by Sohn Young-sung.

Unbowed: Unbowed (; lit.  "Broken Arrow") is a 2011 South Korean courtroom drama film starring Ahn Sung-ki and Park Won-sang.  It was inspired by the true story of Kim Myung-ho, a math professor who was arrested for shooting a crossbow at the presiding judge of his appeal against wrongful dismissal.

Supporting paragraphs: Kim Sung-ryung The Client (2011 film)
Answer: Sohn Young-sung