Desperate to save her family from ruin, struggling artist Kim Da-eun agrees to a shocking holiday contract: pose as the fake wife of a reclusive, ruthless billionaire CEO, Lee Ji-hoon. The goal? To convince his dying grandfather he's finally found love and ensure the family legacy. It's a simple, six-figure deal with a clear set of rules: no emotions, no messy history, no real feelings.

Problem is, Da-eun recognizes him instantly. He's the boy who broke her heart on Christmas Eve seven years ago, leaving her with nothing but a broken promise and a world of pain.

Now, with a second chance she can't afford to lose, Da-eun finds herself trapped in a gilded cage of her own making. The line between reality and pretense blurs as his carefully convincing performance as a loving husband starts to feel terrifyingly real. Every stolen glance, every unexpected touch, every quiet moment of kindness threatens to shatter her resolve. But when a ghost from his past resurfaces, revealing a secret that connects their pasts in a way she never imagined, their fake marriage becomes a dangerous game.

He's a man with a past he can't outrun. She's a woman with a secret she's desperately trying to keep. As Christmas approaches, the question isn't whether their charade will be exposed, but if their hearts can survive the truth.