About

1. Demons Immortal monsters that feast on humans. They grow stronger by consuming large amounts of blood from the progenitor, Muzan Kibutsuji. They disintegrate into ash upon contact with sunlight and can only be killed by decapitation with a special blade called a Nichirin Sword. Depending on their obsessions and grudges from their human lives, they wield bizarre supernatural powers known as 'Blood Demon Arts.' 2. Demon Slayer Corps An organization of demon hunters, unrecognized by the government, formed a thousand years ago to protect humanity from demons. Numerous swordsmen operate under various ranks centered around the Ubuyashiki family. The nine most elite swordsmen with the highest combat power are called 'Hashira' (Pillars). 3. Breathing Styles A special physical enhancement method used by Demon Slayer swordsmen to rival the overwhelming physical abilities of demons. By expanding the lungs significantly, they supply a large amount of oxygen to the blood and forcibly raise their heart rate. This explodes their basic physical strength to the human limit, granting them power and speed comparable to a demon. 4. Marks Scars resembling demon patterns that manifest on users of Total Concentration Breathing who meet specific conditions. The conditions involve reaching extreme states during intense combat: a body temperature of approximately 39 degrees Celsius or higher and a heart rate of over 200 beats per minute. When manifested, physical abilities are explosively enhanced, allowing one to fight on par with Upper Rank demons. However, there is a curse where life expectancy is shortened, and the user does not live past the age of 25 as a price for squeezing out their life force. 5. Bright Red Nichirin Sword A phenomenon where the blade of a Nichirin Sword temporarily turns a deep crimson. It possesses power as if maximizing the strength of sunlight, explosively degrading a demon's near-immortal regenerative abilities and inflicting extreme burning pain on the cut area. It only manifests when Mark users clash their blades together with great force to generate frictional heat or squeeze their swords with immense grip strength during extreme combat situations. 6. Transparent World A type of extrasensory clairvoyant state that only those who have reached the pinnacle of martial arts can attain. By completely stripping away unnecessary senses and movements, the mind becomes transparent and opens up. One can see through the opponent's muscle contractions, blood flow, and even organ movements in real-time. All flow of time surrounding oneself appears to slow down, allowing one to perfectly predict the opponent's next move and strike their vital points. 7. Infinity Castle A massive stronghold where the Upper Ranks of the Twelve Kizuki and the progenitor demon, Muzan Kibutsuji, hide. The space is distorted in all directions, taking the form of a bizarrely twisted wooden castle. It is controlled by the ability of the demon Biwa Woman (Nakime's Blood Demon Art). With the sound of a biwa, the spatial structure inside the Infinity Castle changes in real-time, and humans from the outside are forcibly summoned. 8. Butterfly Mansion The only specialized medical base for the Demon Slayer Corps, managed by the Insect Hashira, Shinobu Kocho. It is equipped with facilities for treating and recuperating injured members, physical function recovery training, and research on demon venom antidotes. 9. Taisho Era The temporal setting of this work, a chaotic era where old traditions and modern civilization were rapidly mixing. During the day, peaceful modern civilization flows with streetcars and gas lamps, but at night, it becomes a stage for cruel struggles where demons secretly hunt humans in the darkness.