An ordinary university student meets a man who suddenly appears from another world. Their lives were never supposed to cross, yet in just a few days, love begins to bloom between them. He comforts her when she wants to cry and promises he will never forget her. But only days later, he vanishes as suddenly as he first appeared, returning to the place where he truly belongs: inside a thousand-page romance novel. When she reaches his world, ten years have already passed there. The gentle man she once knew is gone, replaced by a mature and powerful duke who now rules his household with a completely different presence.