Go Siwon's dreams are constantly visited by the intelligent and handsome Kang Jinha. In the dream, Jinha keeps mentioning this "incident" that happened between them, but Siwon doesn't remember a thing! And how can it seem so real? Fortunately for Siwon, clues about the beginning of the "incident" appear and Siwon is able to recover his memory little by little. How will their relationship change in the end?