Third World: The Wrong Love Rival
The reason why Nu Shen kept referring to Feng Yu as the uncle was because both their parents were actively involved in the project that restored the earth's atmosphere. At that time Feng Zi's mother and Nu Shen's mother were also working on the project when they fell pregnant. The couples deemed this fate and promised to marry their kids together regardless of gender. As luck would have it the two were a boy and girl. This story was meant to have, a happy ending but things took a terrible turn when Nu Shen's parents and Feng Zi's mother caught a strange illness and died one after the other. Feng Yu also fell sick but he somehow survived. After running some tests he found out that extensive exposure to that crystal caused the illness that ultimately led to the death of his wife and colleagues. When he reported this to President Qie, he was fired.