Two story lines: long thoughts and long memories. Changsi is an elder brother and Changyi is a younger brother. He was originally a child of a famous family, but his family fortune declined, so Changsi studied literature and Changyi studied martial arts, and the two went their separate ways. Changsi opened a pawn shop in the city, and Changyi went to the frontier to join the army. The two parted ways due to some things, and they no longer mentioned the incomplete brotherhood. Chang Si met Mu Cang, who had a mysterious family background, on the battlefield, and Chang Yi met Yu Zhaoyang in an enemy country. This is where the forbidden love between these two began...
Intention: Break traditional thinking and rigid requirements for gender