Captain Yoo Si Jin and Dr. Kang Mo Yeon have been best of friends ever since they met through a common friend. Eventualy, They did become a couple for a time but they call it quits and just stayed as friends as to not hurt each other with disappointments of missed dates and empty promises. They met again at a place called Urk, a war torn country where they sought each other again both are now too comfortable with the idea of them being best buddies and scared that their friendship would be totally destroyed if they gave it another try and it did not work out. 

After everything that they experience on Urk, they become mature and learn that being happy is the most important thing. She came to a conclusion that life is too short and she’s not getting any younger so she decided on having a child using artificial insemination since she doesn’t have a suitor that she like enough. Si Jin, although heartbroken, chooses to be happy for his best friend. For four years, he throws himself into any work or mission available abroad until he got a serious injury.

They met again as a doctor and patient. Feelings long buried came rushing back and he found himself falling for her again. But what about her kid who seems to resemble him in every way? There is no way that the boy could be his right?