Do Hae-Gang is a successful lawyer, but she wants to become more successful. Due to her ambitions, her relationship with her husband, Choi Jin-Eon, deteriorates. At that his time, Choi Jin-Eon meets Kang Seol-Ri who attends the same graduate school. Her personality is pure and enthusiastic, like his wife Do Hae-Gang had in the past. Do Hae-Gang then has an accident and loses her memory. She meets Baek Seok and live as her younger twin sister Dokgo Yong-Gi