Park Hyuk-kwon (born July 11, 1971) is a South Korean actor.
 Park began his acting career in 1993 as a member of the theater troupe Sanulrim.
 He later became a well-regarded supporting actor in films such as "Chaw" (2009) and "Secret Reunion" (2010), as well as the television series "Behind the White Tower" (2007), "Secret Love Affair" (2014) and "The Producers" (2015).
 Park also frequently stars in short films and independent films, notably in "Milky Way Liberation Front" (2007) and other works by Yoon Seong-ho.
Yoo Ah-in (born Uhm Hong-sik on October 6, 1986) is a South Korean film and television actor.
 He rose to fame after starring in the 2010 television series "Sungkyunkwan Scandal".
 Yoo Ah-in is best known for his leading roles in the coming-of-age film "Punch" (2011), melodrama "Secret Love Affair" (2014), action blockbuster "Veteran" (2015), period drama "The Throne" (2015), and the historical television series "Six Flying Dragons" (2015-2016).
Secret Love Affair () is a 2014 South Korean television series starring Kim Hee-ae and Yoo Ah-in.
 It aired on cable channel jTBC from March 17 to May 13, 2014 on Mondays and Tuesdays at 21:50 for 16 episodes.
Maze: Secret Love (; lit.
 "Maze: Secret Love") is a 2015 South Korean/Japanese eroticism/thriller film.
"Secret Love" (Korean: 비밀연애) is a song recorded by South Korean idol group B.A.P.
 It is released as a Digital single on March 3, 2012 through TS Entertainment.
 The song was released as a promotional single for their mini-album, "Warrior EP".
 The song was written by Bang Yong Guk and Kang Jiwon; and features vocals from Song Jieun.
 The music video for "Secret Love" contained behind the scenes footage of B.A.P's "Warrior" and Bang&Zelo's "Never Give Up", and it served as a tribute video for their fans.
Kim Hye-eun (born March 1, 1973) is a South Korean actress.
 Kim began working as an announcer for the MBC network in 1997, first at a local affiliate in Cheongju, then later as a weathercaster of the main news desk in Seoul.
 After eight years, she resigned from MBC in 2004.
 Kim pursued acting in earnest in 2007, and has since starred in films and television series, notably "" (2012) and "Secret Love Affair" (2014).
Ahn Pan-seok (born November 1961) is a South Korean television director.
 Ahn directed the Korean dramas "Roses and Bean Sprouts" (1999), "Ajumma" (2000), "Behind the White Tower" (2007), "A Wife's Credentials" (2012), "Secret Love Affair" (2014), and "Heard It Through the Grapevine" (2015).
 He also directed the film "Over the Border" (2006).
Kim Hee-ae (born April 23, 1967) is a South Korean actress.
 She is best known for her leading roles in Korean dramas such as "Sons and Daughters" (1992), "Perfect Love" (2003), "My Husband's Woman" (2007), "A Wife's Credentials" (2012), and "Secret Love Affair" (2014).
Sungkyunkwan Scandal () is a South Korean historical drama starring Park Min-young, Park Yoo-chun, Yoo Ah-in and Song Joong-ki.
 Directed by Kim Won-seok and written by Kim Tae-hee, it is based on Jung Eun-gwol's bestselling 2007 novel "".
 It aired on KBS2 from August 30 to November 2, 2010 on Mondays and Tuesdays at 21:55 for 20 episodes.
"Secret Love Song" is a song recorded by British girl group Little Mix for their third studio album, "Get Weird" (2015).
 It features guest vocals from American singer Jason Derulo, who co-wrote the song with Jez Ashurst, Emma Rohan, and Tich.
 It was produced by Jayson DeZuzio.
 The group's cover of Derulo's 2015 single "Want to Want Me" inspired him to collaborate with them.
 "Secret Love Song" is a slow ballad comprising pounding bass and melancholic strings.
 The lyrics discuss unrequited and forbidden love, while Derulo's verse details his personal experience of having an affair.

Question: Which South Korean actor appeared in both Sungkyunkwan Scanda and Secret Love Affair?
Answer: Yoo Ah-in