In recent years, cruel and out of ordinary crimes had been occurring more frequently, and revenge cases corresponding had risen as well. Since ancient times, acts like "An eye for an eye" are illegal. But besides the law, revenge had always been something that's commonly accepted. Following the increase in crime, the number of homicides disguised as "revenge" had also increase profoundly.
The government believed that it's necessary to legalize the act of revenge and therefore established an organization to moderate these acts. The organization hands out "Revenge License," or what normal people would call "Murder Pass."