Yeonsu, who lost her father and now bears the burden of supporting her family in place of her ailing mother, one day receives an outrageous proposal from Madam Son—the wife of Assemblyman Yoon, her late father’s longtime friend.

The proposal: to bear the child of Cha Taegeon, the vice president of the Haesin Group, while pretending to be Madam Son’s daughter, Hyein.
Yeonsu firmly refuses, but eventually gives in when Madam Son uses her mother’s health as leverage to blackmail her.

—“You signed the contract yourself. You agreed to have my child.”

As Taegun embraces Yeonsu, the tide of his emotions crashes into her as rage and contempt.
And with each repeated encounter, Yeonsu’s heart becomes more and more conflicted.

As time goes by, the tangled emotions between them begin to stir deeper and deeper blue waves...