Characters:

Park Shin Hye - An Engineering instructor at a local university. She grew up in Busan with her parents who died a few years before she graduated from college. Now she is living independently with a very close friend whom she had known since college days.

Lee Min Ho - An intelligent and wise businessman who works as the CEO of the Haebak Industries. He has a son named Lee Sung Jae whom he adores very much. He ahs a close relationship with his son but without a wife.

Lee Sun Kyung - Lee Min Ho's wife.

Lee Sung Jae - A 7 year old kid who loves puzzles and drawing. He is smart and charesmatic yet sweet at the same time.

Yong Jun-Hyung - Park Shin Hye's best friend whom she confides with when she has problems. 

Song Joonki - A doctor at a hospital in Gwangju. He is charming and very endearing that makes anyone who meets him, like him because of his honesty and truthfulness.

Kang So Ra - Lee Min Ho's childhood friend and first love

The story revolves around an unexpected love and lost love. Lee Min Ho does not know each other but somehow became entangled because of situation arising from their meetup. Watch how they get caught up in a tangle of emotions once the characters meet and form a bond of friendship and love.