What happens when a marriage grows cold? Do Hae Gang (Kim Hyun Joo) is a successful attorney whose marriage is suffering because she puts her career ambitions ahead of her husband, Choi Jin Eon (Ji Jin Hee). As the two drift apart, Jin Eon meets Kang Seol Ri (Park Han Byul), a grad student who reminds him of how his wife used to be earlier in their relationship before she became so consumed with career advancement. Hae Gang then gets into a car accident and loses her memory and assumes the identity of her younger twin sister, Yong Gi, who then falls in love with Baek Seok (Lee Gyu Han). What will happen to Hae Gang and Jin Eon’s marriage now?