Gu Yun is an ordinary young man living in a certain city, but he has had too many extraordinary experiences. Under the baptism of multiple earth-shaking changes in family, friendship, and love, he was once disheartened. In reality and fantasy, in order to find a heart that was not confused, he constantly reflected on himself and could look at everything around him more correctly. Later, an unwavering faith finally allowed him to regain what he had lost, creating a beautiful love story. And the person living behind Gu Yun, although he has never really appeared, is a real existence, and he is also the other half of the cloud.