In a future world co-inhabited by humans and demihumans, there is a strained relationship between the two races. Demihumans were originally created by humans as slaves to serve their society, but a war ensued, resulting in their emancipation. However, they were still relegated to a lower social status.
Canon Passacagilia is an officer in the Special Second Division of the East Side's Police Bureau. Her team's primary responsibility is to investigate and handle crimes involving demihumans. She vigilantly patrols the city streets, providing assistance to whoever needs it.