It's about a younger twin sister being asked to 'temporarily' exchange her identity for the elder twin in a marriage to a rich guy due to some very serious allergic reaction on her face that she needed some time and cosmetic surgery to heal it. She didn't want to miss the chance to marry a rich guy so she had to ask a favour from her estranged younger twin sister. In return she agreed to take care of their sick mother, who is in coma while they exchange their identities.