Nichirin Swords (
Nichirin Swords take on a distinct color when first drawn by its owner, which is why they are also referred to as "Color Changing Katanas". However, the holder is required to have a certain amount of skill, or the blade will not change color.
Nichirin Swords are forged with Scarlet Crimson Iron Sand and Scarlet Crimson Ore, both of which are found on high mountains like the Sunlight Mountain, which is perpetually bathed in sunlight all throughout the year on Mt. Yoko.
Demon Slayer recruits choose their own ore after successfully passing the Final Selection. The ore will then be used by a swordsmith of the Swordsmith Village during the forging process, and the swordsmith will personally bring the weapon to the Demon Slayer.
Each Nichirin Sword contains a handguard, or tsuba, that protects the swordsman from cutting themselves when they have a loose grip. It is located where the handle and the blade meet and can come in a variety of colors and shapes. Based on his appearances in the series, Inosuke Hashibira's Nichirin Swords temporarily had handguards when Kozo Kanamori first presented his newly-forged swords. Afterwards, he made his swords jagged-edged, removed the handguards, and wrapped the hilt with bandages.
|Swordsman||Description of Handguard||Picture|
|Tanjiro Kamado*||A black ring connected to its core by lines with a border of the same color. It heavily resembles a wagon wheel in appearance.|
|Zenitsu Agatsuma||Circular shaped with 4 slight indentations, the center has a silver tone with small triangles and has a golden border.|
|Inosuke Hashibira*||A black ring connected to its core by an arrangement of semicircles, possibly to resemble a fish.|
|Kanao Tsuyuri||Circular shaped with a light pastel blue center and border, filled 3 red sakura flowers and a winding pattern that is light green in color.|
|Genya Shinazugawa||Two hollow ovals that overlap its core and are a dull shade of brown.|
|Kaigaku||Incredibly similar to Zenitsu's handguard, but with a slightly darker core.|
|Giyu Tomioka||Hexagonal shaped with a bronze core and with an overlapping fuschia border.
Tomioka's second blade obtained during the fight against Muzan has a handguard resembling a whirlpool.
|Shinobu Kocho||Flower shaped with 4 petals; The petal has an aqua colored core with an orange border.|
|Kyojuro Rengoku||Shaped like a flame with a red core and an orange border.|
|Mitsuri Kanroji||Shaped like a 4 leaf clover; The leaves have a pink core with a golden border.|
|Muichiro Tokito||Rectangular shaped with hollowed rectangles at each corner.|
|Sanemi Shinazugawa||Abstract shape with 8 points with an overlapping pattern; Each plate has a forest green core with a silver border.|
|Obanai Iguro||Gold circular shape engraved with two snakes connected by several plant-like platterns.|
|Tengen Uzui||Circular shaped with 4 slight indentations and gold in color, there's a maroon ring that connects to the center; it has an outer teal border.|
|Yoriichi Tsugikuni||Circular shaped with 4 slight indentations, with a black center and a golden border.|
|Kokushibo||Circular shaped with 4 slight indentations, a center with 3 eyes and several black veins and a golden border.|
*Tanjiro began using Kyojuro's handguard as of Chapter 129.
*Inosuke removed the handguard shortly after receiving the reforged sword.
*Although Kaigaku replaced his Nichirin Sword for one constructed of Demon flesh, his new sword appears to have the same handle and tsuba as his old one.
Nichirin Swords change color depending upon the user, making each blade unique. They can be of many colors. Zenitsu Agatsuma's blade is unique in that its coloration does not form as a solid band but instead as a lightning motif down the length of the blade. The reason for this patterning is unknown.
Each color is said to impart certain properties to the blade. The properties of black Nichirin Swords are not well understood, causing them to be considered a bad omen that the Demon Slayer will not go far (due to dying before much can be learned about the blade).
By raising the temperature of the blade, a Nichirin blade will turn red. Bright Red Nichirin Swords hamper the regeneration of demons and in some cases even burn them on a cellular level leaving wounds that are unable to heal. The creation of the Bright Red Nichirin swords is the transfer of heat. Throughout the series, they have been 3 ways red Swords have been achieved. These ways include using Nezuko Kamado's Blood Demon Art, raising the temperature of the blade with a strong grip, and clashing two Nichirin Swords together (the last two ways can only be achieved when the Demon Slayer Mark is present).
|Flower||Light Pink||2||Kanao Tsuyuri|
|Moon||Light Purple||1||Michikatsu Tsugikuni|
- Their namesake contains the kanji for "sun" (
日nichi?), "ring" ( 輪rin?), which could translate to either "sun ring" or its most common meaning, "solar." In addition to the kanji for "sword/blade" ( 刀tō?), the full translation to the Nichirin Sword is "solar blade."
- The ore used to forge the swords are likely based off of Hihi'irokane, which literally means (Brilliant Scarlet Metal), a legendary metal of Japanese myth that shines brightly in a manner that it resembles flames or the sun. The metal is considered to be similar to other mythical ores such as Orichalcum of Greek and Roman myth and as such is said to have had magical properties.