Unknown entities known as "Witches" roam the cities. They exist solely to destroy humans and turn them into one of the Witches. There is a sector in the government known as the Suppression Corps that specializes in dealing with these Witches, who are completely immune to conventional weaponry. Hansel Takamine is the leader of this group, and has an extreme hatred towards the Witches. With his sword imbued with the powers to eradicate Witches, he fights to avenge his sister who was murdered by these monsters.
Carnaval Glare provides examples of:
- Expy: The mysterious girl that helps Hansel fight the witch on chapter 01, to Kagamine Rin.
- Heroes Prefer Swords: Hansel certainly does, and it works.
- He Who Fights Monsters: Again, Hansel, the title of the first chapter even lampshades this fact, not that he doesn't have a Freudian Excuse to do so, but still it's there.
- Katanas Are Just Better: While everyone prefer to fight the witches with ranged weapons, Hansel's Weapon of Choice is a sword that looks too similar to a katana without the tsuba (handguard). He even gets called on for this by one of his subordinates, but still, it seems to work better than any gun.