From the outside, Han Sun Joo’s life has always appeared to be nothing short of perfect. Born into a wealthy family, Sun Joo and her younger brother, Han Jung Won, were raised without a care in the world. Now as adults, Jung Won has grown up extraordinarily warm-hearted, allowing him to maintain an unwavering sense of optimism while Sun Joo has become the ideal married woman, with a gorgeous home, a devoted husband and two beautiful children. Unfortunately, Sun Joo’s perfect life is on the verge of collapse.

Absolutely penniless when he married Sun Joo, Shin Myung Seop has spent the entirety of his married life slowly climbing the ranks of his mother-in-law’s company, the LaReine Group. Now well-established in his career, Myung Seop appears to be a devoted husband and father, yet when he meets Yoon Mi Ra, things take a complicated turn. Unable to hide his growing feelings for Mi Ra, Myung Seop pursues her and is pleased to find she reciprocates his feelings. Soon entangled in a secret affair, Myung Seop and Mi Ra live in constant fear of discovery.

Hyun Woo fell in love with Soo Yeon at first sight in college and they have been married for 8 years. He thought he had the perfect family, with Soo Yeon, who is a beautiful wife and a good mother to his beloved son. Then one day, Hyun Woo sees a hotel reservation message sent by a male stranger on Soo Yeon’s phone. Even though he tries not to think about it, proof after proof is revealed, which confirm that his wife is indeed having an affair. Since he firmly believes that he is a good husband and father, he can’t seem to forgive his wife. He blames her for putting the family in danger but then starts thinking, “Have I been a good husband to my wife?”

Son Ji Eun is a housewife who works part-time at a mart. She is quiet and sincere, even as she feels trapped in her unhappy life and lonely marriage. One day, she meets biology teacher Yoon Jung Woo and her heart starts beating again. They both know that only ruin will await them, yet they cannot seem to stay away from each other.

A coincidental switch of cars leads to a switch of fates for twins who were separated 30 yers ago. Hae Kang, the elder sister is a successful lawyer married to Jin Eon the successor of a top pharmaceutical company. Their love marriage is shattered by the death of their daughter and her husband's affair with Seol Ri, which ultimately leads to their divorce. But before the divorce is officially declared, Yong Ki switches cars with Hae Kang to avoid being followed by people who are after her life. Yong Ki is the younger sister who is a pregnant widow trying to uncover the secrets behind her husband's sudden death.

After the fateful encounter, Hae Kang ends up in a horrible accident (in the switched car) which makes her lose her memories. Baek Seok saves her and allows her to live with his family till she recovers but mistakes her to be his first love Yong Ki.

Hae Kang as Yong Ki is no longer a cold and reserved person, instead she's warm, cheerful and caring. As Seol Ri and Jin Eon are in talks for marriage, he accidentally runs into Yong Ki. He is shocked at first but gradually begins suspecting that she's his wife and falls for her newly discovered bright self. She's shaken by his arrival too.

Everything seems perfect in the life of the successful family doctor and associate director, Ji Sun Woo. She lives happily in Gosan with her handsome husband Lee Tae Oh, whom she financially helped establish an entertainment company, and their teenage son, Joon Young. However, the perfect image of a happy, loving family life shatters when she discovers that her husband is having an affair, and even their mutual friends are helping him conceal it. Devastated by the betrayal, she sets on a path of seeking revenge and recollecting her broken self.