Nancy has spent her entire life fighting to survive, believing that love is a luxury she can never afford. Min-Jae, on the other hand, is a cold, powerful billionaire heir who believes emotions only make people weak.When family pressure forces Min-Jae into a contract marriage, Nancy becomes the last person he expects to be his wife. Their agreement is simple: no love, no interference in each other's personal lives, and complete obedience to the rules.But living under the same roof changes everything.Behind Min-Jae's arrogant attitude lies a man carrying the weight of painful family expectations. Behind Nancy's quiet strength is a woman determined to protect her heart. As fake smiles slowly turn into genuine feelings, secrets from the past, jealous rivals, and dangerous betrayals threaten to destroy the fragile bond growing between them.Can two strangers who promised never to fall in love break the rules of their contract? Or will the very agreement that brought them together become the reason they lose each other forever?Sometimes, the greatest love stories begin with a signature... and end with a promise from the heart.