Cha Jung-won, who has had a tough life after being abandoned by her biological mother and having her father falsely accused of murder, and growing up in poverty. Her so-called best friend, Joo Young-chae, betrayed her trust by stealing her design and getting accepted to study abroad. Although Jung-won thought she'd long moved on, Young-chae's betrayal still stung. But when Young-chae steals her design again, Jung-won decides she's had enough and sets out to reclaim what's rightfully hers, refusing to show kindness to someone who doesn't deserve it. Joo Young-chae, who used to mockingly call Jung-won by her name, finds herself in a difficult situation. She asks Jung-won to impersonate her, allowing Young-chae to escape her controlling mother and start anew with her lover abroad. As Jung-won takes on Young-chae's identity, she's met with admiration, but slowly, her true self gets overshadowed. She enjoys being the rich daughter, and despite it being fake, she feels so alive. Before her wedding day to Jin Se-hoon, Jung-won discovers a shocking truth about her mother-in-law – they're biologically related. A paternity test confirms the truth. Seeing her mother's luxurious life starkly contrasts with her own struggles, Jung-won seeks revenge by marrying her stepson and starting a war of lies.
