Question: Yeo Jin-goo played the young version of the lead role in which 2008 South Korean erotic story? 

Context articles: Orange Marmalade (TV series)
Mun Che-yong
Hwayi: A Monster Boy
A Frozen Flower
Jackpot (2016 TV series)
Warriors of the Dawn
Reunited Worlds
Shoot Me in the Heart
Yeo Jin-goo
Circle (TV series)

Orange Marmalade () is a 2015 South Korean television series based on the webtoon of the same name which was serialized on Naver from 2011 to 2013.
 Starring Yeo Jin-goo, Kim Seolhyun, Lee Jong-hyun and Gil Eun-hye, it aired on KBS2 from May 15 to July 24, 2015 on Fridays at 22:35 for 12 episodes.
Mun Che-yong (born 1979) is a South Korean film director and screenwriter.
 Mun was assistant director of the films "All for Love" (2005) and "" (2006).
 His directorial debut "Shoot Me in the Heart" (2015), starring Lee Min-ki and Yeo Jin-goo, is based on the award-winning novelist Jeong Yu-jeong's bestselling novel of the same name.
 The film was invited to the 28th Tokyo International Film Festival in 2015.
 His short film "Twins" (2007) won the Best Film in A Short Film About Love at the 2007 Mise-en-scène Short Film Festival.
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!
".
A Frozen Flower () is a 2008 South Korean historical erotic film.
 It is directed by Yoo Ha and stars Jo In-sung, Joo Jin-mo and Song Ji-hyo.
 The historical film is set during Goryeo Dynasty and is loosely based on the reign of Gongmin of Goryeo (1330–1374), but it does not strictly comply with historical facts.
 The controversial story is about the characters’ violation of royal family protocol and their pursuit of love.
Jackpot (), also known as The Royal Gambler, is a South Korean historical drama starring Jang Keun-suk, Yeo Jin-goo, Jun Kwang-ryul, Choi Min-soo, Yoon Jin-seo and Lim Ji-yeon.
 It replaced "Six Flying Dragons" and aired on SBS on Mondays and Tuesdays at 22:00 (KST) from March 28, 2016 to June 14, 2016 for 24 episodes.
Warriors of the Dawn (Hangul: 대립군; Hanja:代立軍; RR: "Daeripgun"; lit.
 Proxy Soldiers) is a 2017 South Korean historical film by Jeong Yoon-cheol set during the 1592 Imjin War, starring Lee Jung-jae and Yeo Jin-goo.
 The story follows a group of mercenaries tasked with protecting the newly crowned prince Gwanghae during a long and treacherous journey vital to the country’s future.
 The film was released on May 31, 2017.
Reunited Worlds (Hangul: 다시 만난 세계 ; RR: "Dashi Mannan Segye " ) is a South Korean television series starring Yeo Jin-goo and Lee Yeon-hee.
 It aired on SBS from July 19 to September 21, 2017 on Wednesdays and Thursdays at 22:00 (KST) time slot for 40 episodes.
Shoot Me in the Heart () is a 2015 South Korean drama film directed by Mun Che-yong, and starring Lee Min-ki and Yeo Jin-goo.
 It is based on the bestselling novel of the same name by Jeong Yu-jeong, which won the Segye Literature Award in 2009.
Yeo Jin-goo (born August 13, 1997) is a South Korean actor.
 Yeo began his career as child actor, debuting in the film "Sad Movie" (2005).
 Nicknamed "Nation's Little Brother", he went on to play the younger version of the lead roles in movies and television dramas such as "A Frozen Flower" (2008), "Giant" (2010), "Moon Embracing the Sun" (2012), and "Missing You" (2012).
 He is known for playing the title character in action thriller "" (2013), for which he won Best New Actor at the Blue Dragon Film Awards.
Circle () is a South Korean television series starring Yeo Jin-goo, Kim Kang-woo, Gong Seung-yeon, , , Lee Gi-kwang and .
 It is scheduled to air on tvN every Mondays and Tuesdays at 23:00 (KST) starting May 22, 2017.