Demon Slayer: Why Tanjiro's Sword Is Black & Other Nichirin Blade Colors Explained

Anime and manga have far outgrown their niche status as far as pop culture is concerned. In fact, thanks to the rise of multiple mega-popular series, both art forms currently have higher visibility than ever. But what makes a show like "Demon Slayer" stand out among the countless anime series out there and have the kind of impact that it does?

While "Demon Slayer's" gorgeous animation is no doubt a large part of its appeal, the show's dense lore is one of its strongest features. Take, for example, the Nichirin Swords' role in the show. These color-changing blades are forged from special sand and minerals that absorb sunlight, allowing the wielder to kill demons permanently.

As fans are aware, the weapons are pivotal to the goals of the show's protagonists. Still, they remain somewhat mysterious in terms of how they change based on their wielders. We see this firsthand when Tanjiro (Natsuki Hanae/Zach Aguilar) gets his new sword at the tail end of Season 1, only for it to turn an ominous black.

The dark color of Tanjiro's sword is seen as a bad omen by some, as a black blade might suggest not having the strength to leave a mark on demons. However, according to the lore of the show, black also symbolizes the sun, which means that the sword's shadowy appearance might be a good thing. However, some "Demon Slayer" fans may be wondering what the other colors mean beyond Tanjiro's unusually-hued blade.

While the mysteries of the Nichirin blades in "Demon Slayer" will continue to unfold as the show heads toward its inevitable conclusion, we have enough hints about the nature of the blades and how they're constructed to make a few assertions about what their coloring means and how it affects the series.

Much like Tanjiro's, the swords used by other members of the Demon Slayer Corps. are also reflections of the traits of their wielders. For instance, while Zenitsu (Hiro Shimono/Aleks Le) is often depicted as a coward, the sleeping warrior within him causes his sword to bear markings that reveal his thunder-breathing prowess. Similarly, Muichiro's (Kengoku Kamanashi/Griffin Burns) blue sword and Mitsuri's (Kana Hanazawa/Kira Buckland) pink sword are indicative of their breathing styles. Still, this raises further questions regarding another of the central characters in "Demon Slayer" — Inosuke (Yoshitsuga Matsuoka/Bryce Papenbrook).

Inosuke's blades are serrated but otherwise standard in their appearance, despite having the ability to kill demons just as effectively as the blades of any Hashira. Though we still don't know how Inosuke got his dual blades, the fact that he lived a barbaric lifestyle in the mountains before audiences are introduced to him does suggest that he may have gotten the blades illegitimately. However, the possibility also exists that he gained his weapons through legitimate means. Inosuke's beast-breathing style is said to have an indigo-grey coloring, meaning he could have been the one to change them to this shade.

In the wake of the Swordsmith Village arc, it's probably fair to say that we know more about the Nichirin swords and how they're made than ever before. However, with the Hashira Training arc right around the corner, it's possible we'll gain even more insight into the blades as well as their wielders.