Why Is Tanjiro’s Sword Black In Demon Slayer? Anomaly Explained!

Anomalies are common in the world of Demon Slayer, but none as peculiar as the case of the black nichirin blade. Read ahead to know what it truly signifies!


Unsheathing your sword to finally know its color must be an exciting time for a new demon slayer! But, what if it turns out to be a black sword?

Well, that’s exactly what happened with Kamado Tanjiro. As the color slowly swirled upwards from the hilt to the tip, it becomes more obvious that this is no sign of good fortune.

When one looks at the bright blades of other characters (you can read about them here), it makes the black Nichirin blade more mysterious.

There is not enough information about the black blade, but that hasn’t stopped it from becoming one of the most popular topics for fans to talk about!

So, is it just a bad omen or a symbol of Tanjiro’s importance? Read more to find out!

Why is Tanjiro’s nichirin sword black? Meaning and anomaly:

To answer in short, Tanjiro’s sword is black mostly because he is a user of multiple breathing techniques including sun breathing, and also to signify that he will go through a lot of hardships in his life. Read on to know a detailed explanation.

As with usual connotations of black, a black nichirin sword doesn’t signify the happiest of things.

For one, there are not enough black sword users that one could base anything off of. Its because most who did end up with one, did not live for long. For demon slayers, they are not really the brightest of omens.

As mentioned in the manga, the scarce number of black nichirin sword users is the reason why less is known about it. It is said to be the mark of an unsuccessful swordsman.

information on black nichirin blade
Demon Slayer Manga Chapter 9

While this put an ominous cast over Tanjiro’s own future, he has till now proved all of these assumptions wrong by turning out to be an impressive swordsman in his own right.

Therefore, does the black blade signify the trials and tribulations one may face later on? While the other characters have suffered immensely, Tanjiro’s story ties back to centuries ago with that of Yoriichi Tsugikuni, which could probably emphasize his own suffering and role which lead to the black blade.

Ancient ties aside Tanjiro has gone through enough in a short span of time, which would eventually put him on the path to become a demon slayer. Whole family murdered? A sister who is a demon? In the crossfire of Michael Jackson with fangs? Nope, not a good life!

On the other hand, Haganezuka, looking at Tanjiro’s appearance, predicted that he would end up with a red blade that would signify his good luck and his family’s work with fire.

Tanjiro’s whole name in fact symbolises his connection with charcoal and fire; the kanji for “tan” meaning charcoal, the first half of his surname “kama” is a Japanese furnace that is used with charcoal.

But, more on that later. First, let’s look at the information that Kyojuro Rengoku had.

Rengoku’s knowledge of the blade

Rengoku gave us some valuable input on how breathing styles came to be and their connection to nichirin swords. As we know, each style seems to have its own color coding.

While he lists the basic five breathing styles, there is no mention of the Sun Breathing. This is because nobody had heard of “Hinokami Kagura” before.

So firstly, that means that the colour denoted for Sun Breathing is unknown.

More importantly, Rengoku mentions that he personally too has never seen a black nichirin blade swordsman before. Other than that, he mentions two more important things.

Firstly, no black blade user has ever been a Hashira. This again ties down to the aforementioned belief that black blade swordsmen don’t make it far off in the corps. Also, judging by how Tanjiro was not able to become a hashira till the end, this information still holds out to be true!

Secondly, he mentions that this blade signifies those who can’t find any one breathing style to stick to.

Rengoku talks about what he knows about a black nichirin blade
Demon Slayer Manga Chapter 54
Rengoku explains to Tanjiro whatever he knows about breathing styles and the black nichirin blade.

This would make a lot of sense in Tanjiro’s case. Tanjiro started off with Water Breathing before discovering Sun Breathing/ Hinokami Kagura.

He uses both styles thereafter. Therefore, the dual nature of Tanjiro’s style of breathing could probably serve as evidence for what Rengoku said.

Warning: The next section contains spoilers from the Demon Slayer manga. Read ahead at your own discretion.

Do Sun Breathing users have black nichirin swords?

As mentioned above, Tanjiro’s importance in the conflict is centuries old. This is why his Hanafuda Earrings or Hinokami Kagura are no ordinary family heirlooms.

This is due to one of his ancestor’s strong friendship with the progenitor of breathing styles: Yoriichi Tsugikuni.

Yoriichi was the one who invented breathing styles, coming up with Sun Breathing.

Due to its complex nature, however, no one (or at the most, very few) were able to learn it, which is what gave birth to the other five basic styles as students incorporated the learnings into their ways.

Muzan managed to strike down any Demon Slayer Corps member who could manage to learn Sun Breathing. Therefore, all information about this style was lost.

To make matters worse, Kyojuro’s father, Shinjuro vandalised the records that could have had some information.

Senjuro apologises as Shinjuro ripped up the records which would have had an insight on Sun Breathing and the black nichirin blade
Demon Slayer Manga Chapter 69
Kyojuro’s younger brother, Senjuro, apologises to Tanjiro over the ruined manuscripts of Hashira records.

Putting that aside, Yoriichi’s life was nothing short of a tragedy.

If black blades are representative of the sadness that sits inside the heart of someone, suppressed by their resolve to keep moving forward, then it makes sense that both Yoriichi and Tanjiro ended up with black blades.

Tanjiro himself saw his life change in under a night, bidding goodbye to his happy life.

While this is not meant to invalidate the struggles of the other characters, some who arguably suffered worst background stories than Tanjiro, both Yoriichi and Tanjiro have similarities.

Both saw their siblings becoming demonized and suffered the horrors of picking up a sword and watching comrades die.

The seemingly tragic lives of both Sun Breathers is why its a popular fan theory that their blades are black.

While there is no confirmation that Yoriichi has a black blade, the design and seemingly no mention of any other colour has made fans assume that he wielded a black nichirin blade after all.

Light absorption and black

On a more practical note, there is another reason why Sun Breathers may have a black blade. As we know, nichirin blades absorb sunlight, which is what kills a demon.

Therefore, what if black represents the ability of absorbing the most sunlight, which would signify Sun Breathing?

Black is actually not a colour, but the absence of it! Also if you paid enough attention in school, you’d know that black is the best absorber of sunlight.

Keeping this in mind, it would make sense if black blades absorb the highest amount of sunlight per blade. However, to put this excessive amount of sunlight in use would require a breathing style that could keep up with it.

With Sun Breathing being the creator of all other styles, its arguably the most powerful.

Therefore, the best way the Sun can be helpful is when its rays are used to their full capacity. Therefore, black could signify the blessing of the sun that the users have in the form of a black nichirin blade.

Additionally, black also absorbs all colors. Being the first breathing style that gave birth to other styles, it would symbolically further make sense why the Sun Breathing style users have black blades.

Does Tanjiro’s sword turn Crimson red?

While a black blade may be an anomaly, it is still a nichirin sword after all. There is no records for black blades not working similarly to their other colored counterparts.

The only difference that a black sword has from others is the lore and omens attached to it. Therefore, yes, black blades can turn crimson red if they meet one of any conditions written below.

So to answer in short; Tanjiro sword does turn red. But this is not the usual red of the flame Hashira, but a crimson red color. Even Yoriichi managed to get their blades to turn crimson.

While Yoriichi’s way was more straightforward, Tanjiro manages to turn his black sword crimson with not only his demon slayer mark but Nezuko’s Blood Demon Art as well.

We see this in the fight against Rui, Nezuko’s Blood Demon Art technique “Exploding Blood” allowed Tanjiro’s blade to turn crimson.

A nichirin blade exceeds its powers and capabilities when it turns crimson red. This is different from the usual red of the nichirin blade of a Flame Hashira. 

The main factor in triggering the change is increasing the temperature of the blade. This can be done in three ways:

Firstly, if a user grips their sword and pours all their strength into the nichirin sword it can turn red. The strength of the user results in the blade’s temperature rising.

Obanai mentions that the blade turns red when the user is “pushing himself to the brink of death”.

Obanai Iguro's nichirin blade turns crimson.
Demon Slayer Manga Chapter 189
Obanai’s lavender nichirin blade turns crimson red. He says its because of a “grip like a vise”.
  • Secondly, if a user creates friction between their weapons it can also result in the blade turning crimson red due to heat.
  • Lastly, we see Tanjiro use Nezuko’s Blood Demon Art to set his sword on fire, giving it the temperature it needed to turn all red.

A demon slayer mark is essential for using the first two ways.

Yoriichi was the first demon slayer to activate the crimson red nichirin blade.

This nichirin blade can prove extremely dangerous to demons as it can hamper regeneration and also burn their cells. Kokushibo firsthand experienced the strength of a crimson red blade, describing it as feeling like his insides were seared.

Do you think the black blade is actually the sign of a Sun Breathing user, or Rengoku’s information has more mettle? Let us know in the comments!

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