A promise made forty years ago had brought two unknown people to get married. They don’t love each other. As they spend more time together, they started to fall in love with each other. But, he couldn’t betray his girlfriend. She couldn’t make him to choose. Lee Xiumin (29 years old)-The eldest son of the Lee’s family. He is the strict boss in the eyes of his employees. But, he is the caring and friendly guy when he is with his friends and his loved one. One day, a girl entered his world and started to make him lose focus.Kang So Ra (23 years old)-The only child of the Kang’s family. She could mix around easily with strangers and be friendly to anyone. She knew that he loved someone else, but she couldn’t stop herself from falling in love with him. She couldn’t let him choose, because she’s afraid to know the answer.