In this world, people are divided into "Civilians" and "Killers." Civilians are ordinary citizens—as the name implies, just perfectly normal humans. And Killers are those who harm and attack these Civilians. Periodically, Killers come to hunt the Civilians. Usually about once a week. Civilians possess some kind of ability. It might be a way to fight back against Killers, a defense, or some means of escape.

This is not the story of Civilians fleeing from those Killers... but rather a story about the "peaceful" off-days of a Killer.