
Soon, an arranged marriage is set up between the two and they eventually become engaged. Although the two are initially antagonistic towards each other, Jae-ha unwittingly sparks a friendship with Hang-ah and he subsequently falls in love with her.

Both Jae-ha and Hang-ah meet at the joint military training, a crucial part in establishing friendly relations between the two separate countries. Meanwhile, Kim Hang-ah ( Ha Ji-won) is a North Korean Special Forces officer who is also the daughter of a high ranking North Korean military official. 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." 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.

Set in an alternate reality, modern-day South Korea is governed by a constitutional monarchy descended from the Joseon Dynasty.
