Kim Hyojin (you) and Song Ha Neul share a deep bond of friendship ever since Haneul was orphaned and was taken under the custody of Hyojin's parents, Junhyun and Juyeon. Hyojin grows up responsible and compassionate while Haneul, fueled by ambition and envy, secretly detests Hyojin and always feels inferior next to her. Many boys are attracted to Hyojin but she falls in love with Luhan. It doesn't take long before Hyojin becomes pregnant and gives up on her dreams of becoming a nurse in order to marry Luhan. Although their marriage is void of happiness, Hyojin tries to be an excellent wife to her husband, and takes good care of her in-laws, Xi Yung Zhae and Xi Woori. However, she soon learns that the life she chose is full of lies and betrayals. Adding to her woes is her unexpected miscarriage. She soon discovers that Luhan is cheating on her and shocked to learn of Haneul’s treachery. Hyojin is devastated by the thought of being betrayed by the two people closest to her heart. Luhan decides to end his affair with Haneul but Haneul is already pregnant with his child. He chooses to live with her as Hyojin is forced to go back and stay with her parents. But Hyojin finds out that she, too, is pregnant with Luhan's child. Hanetl then tries to get rid of that child but ends up drowning Hyojin herself by accident. But by a twist of fate, Hyojin survives and is back for revenge. She assumes the identity of another woman as Seol Hana and seeks out vengeance against Luhan and Haneul. Now, it's time for pay back and Hyojin will do everything to taste the bittersweet part of her revenge.