Vibrant and charming, but as passionate as one can get when it comes to work, fashion consultant Yu-Na (Uhm Jung-Hwa) lead on a cheerful life with her husband - humorous and sentimental hotelier, Min-Jae (Park Yong-Woo). But with 4 years of dating and 3 years of marriage, their love life is more consoling than passionate. Cold-hearted to women and a serious workaholic, Young-Jun (Lee Dong-Gun) is an object of envy to others, with intellectual yet calm lighting designer So-Yeo (Han Chae-Young) by his side. But only husband and wife by law, there's nothing fidgety in their marriage. Getting involved in a provocative tussle with Yu-Na, on her visit to consult his wardrobe -Young-Jun. Meeting Min-Jae like fate in unfamiliar Hong Kong - So-Yeo. So-Yeo is shaken by Min-Jae, who carefully looks into her inner self, while Young-Jun can't seem to forget Yu-Na, always tough but with plenty of reservation. That night, the two couples spend the most intimate time of their lives - Both wrongdoers and victims, they have yet to realize what their partners were involved with. What will happen to them? What will be their final choice?