"This judgment will not let a single soul escape."Kazuki's foster parent was murdered by villains right in front of his eyes. Unable to put up any resistance, the young boy could only taste absolute helplessness.The "Tokyo Demon Realm," a space fused with another world, is a maddening, lawless zone where those who commit crimes grow wealthy and only the wicked prosper. Now, Kazuki is on the verge of losing not just his foster parent, but his beloved younger sister, Akina, as well.When his hatred for the villains reaches its absolute peak, a sinister god appears before him and grants him a mysterious power: [Villain Slayer].It is a class that only permits the killing of evildoers—a job that grows stronger with every life it takes. Hiding his rage behind a mask, Kazuki begins reaping sinners with his jet-black "Villain Scythe." To save his sister, the lonely avenger's merciless hunt begins!