Song Hye Kyo is an angel. Literally.  One of the best angels sent to guide and guard people's souls in South Korea, she always got serious duties, and felt tired of it.  For once, she asked for "an easy job". The Angel's Headquarter (yes, there is a headquarter for angels) gave her "an easy case". A handsome man who got cruelly betrayed by the woman he was planning to marry, until he nearly committed suicide. His name was Song Joong Ki.  Hye Kyo's mission was:

Still very new in their relationship, Hye Kyo didn't really believe when Joong Ki said he'd follow her to New York...........

Song Joong Ki has been a fan of Song Hye Kyo since he first saw her on TV. It escalates when they start to work together for Descendants of The Sun. On their last day shooting in Greece, he figures that it's now or never to tell her his feelings......