Cha Do-kyung was an “it girl” and center of the attention during her school days. Thanks to her looks and affluent family background, she was surrounded by many suitors and admirers. On the other hand, Jang Gong-sim, Do-kyung’s friend, who always lagged far behind Do-kyung in every aspect felt inferior to her while growing up. However, Do-kyung’s accidental one-night stand with Bong-hee, Gong-shim’s then boyfriend, led to an unwanted pregnancy with twins. Do-kyung and Bong-hee’s subsequent marriage made the two women live a very different life. Do-kyung becomes an ordinary homemaker while betrayed Gong-shim who went to overseas to pursue her study becomes a celebrity which could have been Do-kyung’s fate. Their reversed situation makes them at odds with each other and they end up fighting over Hyun-woo who once had a crush on Do-kyung when young. Torn between the two women, will Hyun-woo stick to his first love who became another man’s wife or will he decide to marry Gong-shim, the ugly duckling turned into the beautiful swan? Will Gong-shim’s efforts to win Hyun-woo’s heart be successful?

Han Young Min (Lee Jung Jin) and Min Seo Young (Oh Seung Hyun) were engaged to be married; however, Young Min's ex, Jae Hee (Kim Yoo Mi), dumped their son, Jun, on him. Seo Young broke up with Young Min afterwards because Young Min refused to send his son back to his mother. Jo Min Soo (Lee Yoo Ri) befriends Young Min and helps Young Min adjust to his new life with his son. Young Min and Mi Soo soon realize their feelings for each other and plan to marry. However, obstacles stand in their way before they can do so.

Ma Young-Hee (Kim Jung Hwa) has been in love with her best friend Han Jin-Woo (Yeon Jung Hoon) since the first time they met in high school. Han Jin-Woo, on the other hand, does not see Ma Young-Hee's love for him and blindly goes out with other girls in front of Ma Young-Hee. On a trip to Japan, Young-Hee meets a young man on the street who takes her back to his apartment since she is drunk. Young-Hee accuses this man of raping her even though he didn't, but before she can rightfully press charges, he runs away as the government officials of Japan chase him down for an expired visa. Upon returning to Korea, Jin-Woo stops by her apartment and introduces his younger brother, Han Sun-Woo (Lee Wan) who just happens to be the young man she met in Japan. Jin-Woo asks if Sun-woo may stay at her place, and Young-hee accepts out of love for Jin-Woo. The story unfolds as a sudden high school classmate of Young-Hee, Jang Hee-Won, (Oh Seung Hyun), begins to court Jin-Woo.