Which series did Kim Ji-won star in first, Gap-dong or The Heirs?
Gap-dong: Gap-dong () is a 2014 South Korean television series starring Yoon Sang-hyun, Sung Dong-il, Kim Min-jung, Kim Ji-won and Lee Joon. Kim Ji-won (actress):  She gained attention through her roles in television series "The Heirs" (2013), "Descendants of the Sun" (2016) and "Fight for My Way" (2017).
The Heirs