Cagaster of an Insect Cage

At the turn of the 22nd century, a powerful explosion shook the Earth, followed by the sudden spread of a mysterious disease that came to be called Cagaster. Humanity was utterly unprepared for it. The infection spread with astonishing speed, engulfing entire regions, and those who succumbed to it turned into terrible mutants resembling giant insects. These creatures attacked healthy people, infecting them and turning them into their own kind, and their numbers grew day by day.

Only a handful could stand up to the monsters, and there was no effective means of destroying them. Abandoned towns and villages became breeding grounds for new swarms. Thirty years after the outbreak, in 2125, one young man stands out amid the chaos: Kidou, a seventeen-year-old exterminator who has become famous for his exploits. His services are often hired by an influential merchant who regularly makes dangerous journeys on business. One day, on one of their routes, they come across a dying man lying by the road in a ruined village. On the brink of death, he begs Kidou to save his daughter Ilie and take her somewhere safe.