Question: Who starred in Jo Jin-kyu's 2016 film "Sweet Sixteen"?
Context: Sweet Sixteen (, literally combining the names of the main characters) is a 2016 Chinese-South Korean romance film directed by Jo Jin-kyu and starring Kris Wu, Han Geng, Joo Won and Lu Shan.  It was released in China by Heng Ye Film Distribution on August 5, 2016. The 2009–10 Xavier Musketeers men's basketball team represented Xavier University in the 2009–10 college basketball season.  This was head coach Chris Mack's first season at Xavier.  The Musketeers competed in the Atlantic 10 Conference and played their home games at the Cintas Center.  Xavier finished the season with a record of 26–9; 14–2 in A-10 play to capture a share of the regular season championship with Temple.  The Musketeers lost in the semifinals of the 2010 Atlantic 10 Men's Basketball Tournament to Richmond.  Xavier received an at-large bid to the NCAA Tournament, as a #6 seed.  They defeated Minnesota and Pittsburgh to advance to the Sweet Sixteen.  In the Sweet Sixteen, they fell to Kansas State in double overtime. My Wife Is a Gangster () is a 2001 South Korean film directed by Jo Jin-kyu; it's about a female gang boss who needs to get married to fulfill her dying sister's wishes.  A sequel, "My Wife Is a Gangster 2", was released in 2003, with a third ("My Wife Is a Gangster 3") released at the end of 2006. The 2016–17 Purdue Boilermakers men's basketball team represented Purdue University in the 2016–17 NCAA Division I men's basketball season.  Their head coach was Matt Painter, in his 12th season with the Boilers.  The team played their home games in Mackey Arena in West Lafayette, Indiana and were members of the Big Ten Conference.  With their win over Indiana on February 28, 2017, Purdue clinched at least a share of the Big Ten regular season championship.  With Wisconsin's loss on March 2, Purdue clinched an outright championship, their 23rd championship, the most in Big Ten history.  They finished the season 27–8, 14–4 in to win the Big Ten regular season championship.  In the Big Ten Tournament, they lost in the quarterfinals to Michigan.  They received an at-large bid to the NCAA Tournament as the No. 4 seed in the Midwest Region where they beat Vermont and Iowa State to advance to the Sweet Sixteen.  In their first trip to the Sweet Sixteen since 2010, they lost to No. 1-seeded and No. 3-ranked Kansas. The 2016–17 Butler Bulldogs men's basketball team represented Butler University in the 2016–17 NCAA Division I men's basketball season.  Their head coach was Chris Holtmann, in his third year.  The Bulldogs played their home games at Hinkle Fieldhouse and were members of the Big East Conference.  They finished the regular season 25–9, 12–6 in Big East play to finish in second place.  They lost to Xavier in the quarterfinals of the Big East Tournament.  The Bulldogs received an at-large bid to the NCAA Tournament as a No. 4 seed in the South Region.  They defeated Winthrop and Middle Tennessee to advance to the Sweet Sixteen.  In the Sweet Sixteen, they lost to eventual National Champion North Carolina. The 2011–12 Ohio Bobcats men's basketball team represented Ohio University during the 2011–12 NCAA Division I men's basketball season.  The Bobcats, led by fourth year head coach John Groce, played their home games at the Convocation Center and are members of the East Division of the Mid-American Conference.  They finished the season 29–8, 11–5 in MAC play to finish in third place in the East Division.  They were champions of the MAC Basketball Tournament and earned an automatic bid into the 2012 NCAA Tournament where the 13th seeded Bobcats defeated Michigan in the second round and South Florida in the third round to advance to school's first "Sweet Sixteen" since 1964.  They lost in the "Sweet Sixteen" to North Carolina in overtime. The 2016–17 Wisconsin Badgers men's basketball team represented the University of Wisconsin–Madison in the 2016–17 NCAA Division I men's basketball season.  The Badgers were led by second-year head coach Greg Gard, will played their home games at the Kohl Center as members of the Big Ten Conference.  They finished the season 27–10, 12–6 in Big Ten play to finish in a tie for second place.  They defeated Indiana and Northwestern in the Big Ten Tournament, but lost to Michigan in the championship game.  They received an at-large bid to the NCAA Tournament, their 19th consecutive trip to the NCAA Tournament, as a No. 8 seed in the East region.  The Badgers defeated Virginia Tech in the First Round and upset No. 1 overall seed and defending National Champion Villanova to advance to the Sweet Sixteen for the fourth consecutive year.  In the Sweet Sixteen, they lost to No. 20-ranked Florida. Jo Jin-kyu (born 1960) is a South Korean film director.  Jo's directorial debut was the hit gangster comedy "My Wife Is a Gangster" (2001).  He returned to the series with "My Wife Is a Gangster 3" in 2006.  In 2016, he directed a joint Korean-Chinese film "Sweet Sixteen" (2016) starring Joo Won. The 2015–16 Wisconsin Badgers men's basketball team represented the University of Wisconsin–Madison in the 2015–16 NCAA Division I men's basketball season.  This was Bo Ryan's 15th season as head coach at Wisconsin, before he resigned 12 games into the season.  On December 15, 2015, Ryan announced he would retire effective immediately leaving associate head coach Greg Gard as interim head coach.  The team played their home games at the Kohl Center and were members of the Big Ten Conference.  They finished the season 22–13, 12–6 in Big Ten play to finish in a four way tie for third place in conference.  Shortly after the regular season, Greg Gard had the interim tag removed as he was announced as the permanent head coach.  The Badgers were upset by Nebraska in the second round of the Big Ten Tournament.  They received an at-large bid to the NCAA Tournament, their 18th straight appearance in the Tournament.  They defeated Pittsburgh and Xavier to advance to the Sweet Sixteen for the third consecutive year.  In the Sweet Sixteen, they lost to Notre Dame. The 2015–16 Texas Longhorns women's basketball team represents the University of Texas at Austin in the 2015–16 college basketball season.  It was head coach Karen Aston's fourth season at Texas.  The Longhorns were members of the Big 12 Conference and play their home games at the Frank Erwin Center.  They finished the season 31–5, 15–3 in Big 12 play to finish in second place.  They advanced to the championship game of the Big 12 Women's Basketball Tournament where they lost to Baylor.  They received at-large bid of the NCAA Women's Basketball Tournament where they defeated Alabama State and Missouri in the first and second rounds, UCLA in the sweet sixteen before last year's sweet sixteen rematch to Connecticut in the elite eight.
Answer: Joo Won