Changyang went to Hunter School for five whole years. What is Hunter School and Why did he go there?

Hunter School is a brutal, highly isolated military academy that puts its recruits through extreme, life-or-death training. It is located in the middle of nowhere and the school cuts its soldiers off from the outside world by strictly prohibiting phone usage, saving it for rare "gap days." The training is so dangerous that soldiers have to sign a paper saying the school isn't responsible if they get hurt or die. The soldiers go on life-threatening missions.

Changyang actually took that time to get trained in a hunter school, which was a matter of life and death. At first, he went there to grow stronger and be able to protect Qinglang from the harsh industry and people. He also wanted to present himself as a capable person in front of Qinglang, rather than being a tea farmer or a nepo kid living off his parents' money while Qinglang was a huge celebrity without anyone else's help.

At first he was a recruit... But as he excelled, he was promoted to a permanent soldier and then he was offered a further promotion that demanded he cut off all outside ties completely, Changyang refused and rather than severing his connection to Qinglang, he retired and went back to Qinglang.