A school called City of Sora holds the secrets of a city. A girl named Mengyu fell from the sky, but she insisted that she and Yang Xin were close friends even though she had never met him before? ! Many strange and contradictory things point the finger of the incident at Chengkong. What exactly is hidden here? Here, can Mengyu regain everything she lost? Can it become an utopia for Mengyu and her beloved?