Nichirin Blades (
Nichirin Blades take on a distinct color when first drawn by its owner, which is why they are also referred to as "The Color Changing Swords". However, the holder is required to have a certain amount of skill, or the blade will not change color.
Nichirin Blades 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.
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 Blade contains a handguard, or tsuba, that protects the swordsman from cutting themselves. It is located where the handle and the blade meet and can come in a varitey of colors and shapes. However based on his appearances in the series, Inosuke Hashibira's nichirin blades do not have handguards
|Swordsman||Description of Handguard|
|Tanjiro Kamado*||Black ring connected to its core by lines.|
|Zenitsu Agatsuma||Circular shaped with 4 slight indentions, the center has a silver tone with small triangles and has a golden border.|
|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 golden 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||Circular shape engraved with a snake|
*Tanjiro began using Kyojuro's handguard as of Chapter 129.
Nichirin Blades 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 Blades 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 with a strong grip, Demon Slayers are able to change their Nichirin Blade's color to red, which prevents demons from regenerating damage done by the blade. Clashing a Nichirin Blade with other Nichirin Blades will also turn them red and give them the same qualities.
|Flower||Light Pink||2||Kanao Tsuyuri|