The story takes place in the Taishō era Japan, where a secret organization, known as the Demon Slayer Corps, has waged a longtime war against demons for centuries. These demons are former humans who possess supernatural abilities such as super strength, rapid regeneration, and unique powers referred to as "Blood Demon Art". Demons can only be killed if they are decapitated with weapons crafted from a rare alloy called Nichirin, injected with a poison extracted from wisteria flowers