The story revolves around Winnie and Sarah, whose lives are switched at a hospital. Winnie, seriously ill, is replaced with the rich girl, Sarah, by her desperate mother. After losing their biological daughter, Sarah's family showers all of their love onto Winnie. In contrast, Sarah, suffering from amnesia, is adopted by Winnie's mother and unaware of her true identity. Sarah and Winnie become classmates. Winnie, the adopted daughter of the Gallagher family, bullies Sarah frequently. Even Sarah's own brother, Henry, unknowingly aids Winnie in tormenting Sarah only to find out later that the bullied girl, Sarah, is his long-lost sister.
