The King 2 Hearts

Set in an alternate reality, modern-day South Korea is governed by a constitutional monarchy descended from the Joseon Dynasty. Lee Jae-ha (Lee Seung-gi) is a handsome yet materialistic crown prince who doesn't care about politics and feels total reluctance to being the second in line to the throne. Lee Jae-kang (Lee Sung-min), the current king, tricks him into joining a joint military collaboration with North Korea as a means to help "make him grow up."[cont.] [About:]'The King 2 Hearts' is a 2012 South Korean television series, starring Ha Ji-won and Lee Seung-gi in the leading roles. It is about a South Korean crown prince who falls in love with a North Korean special agent. The series aired on MBC from March 21 to May 24, 2012 on Wednesdays and Thursdays at 21:55 for 20 episodes.[Source: Wikipedia]