Sa Wol (Baek Jin Hee) grew up in the orphanage with her two best friends, Oh Wol (Song Ha Yoon) and Hye Sang (Park Se Young). Oh Min Ho (Park Sang Won) comes to adopt Hye Sang, thinking she is his biological daughter. However, on the day the orphanage collapses, Hye Sang finds out the true daughter is Sa Wol.
She traps the orphanage manager (her true father) and Oh Wol in the collapsing building and sighs in relief believing they have died. But when Sa Wol is also brought into her new family, she spends the next 25 years tormenting her and burying the truth. But as her web of lies grows, it becomes harder to maintain, and eventually two true friends and their families will be reunited.