Prequel to Doppelgänger

Future City, here is a new and wonderful world. Due to the highly developed science and technology, everything that exists only in people's imagination in the 21st century is within reach here. Sky cities, underground cities, and time travel are all very common sights here. Lion is a person living in the future city. Because Lion developed a new type of drug, he was pursued by the space-time police. Lion escaped to Shanghai and attempted to exchange identities with Lu Chongsheng, the general manager of a pharmaceutical company who looked exactly the same. While getting along with Lu Chongsheng's girlfriend Su Xiaona, he gradually developed feelings for her. When Lu Chongsheng discovers that there is a person who is exactly like him, who has replaced his life and his job, how can Lu Chongsheng get out of the predicament and regain Xiaona's heart?