The story of two married couples in danger of unraveling as the husband and wife find themselves attracted to other people. Na Eun Jin (Han Hye Jin) is a hardworking, positive, and bright woman who encounters feeling of disappointment because of her cheating husband (Lee Sang Woo) and other events, which makes her find the new side of herself. Meanwhile, Yoo Jae Hak (Ji Jin Hee) is a successful CEO, respectable father of two sons, and husband to his devoted wife (Kim Ji Soo). He thought he was happy in his life until he finds himself attracted to Eun Jin and then he begins to reflect on his life and conflicts between responsibility to family and his feelings for Eun Jin.