Is Yoriichi Upper Moon 1 Demon? Is Yoriichi Related To Tanjiro In Demon Slayer?


With Demon Slayer season 3 episode 1 airing across the globe fans have been hit with several mysteries in the first episode. The episode starts with Tanjiro dreaming of Yoriichi the legendary Sun Breathing Demon Slayer who sent shivers down Muzan’s spine. At the same time, the episode ends with Tanjiro seeing him for real in front of him.

This led to the birth of many questions in the minds of all fans. It arose questions like Is Yoriichi Tanjiro’s father? Is Upper Moon 1 Demon Kokushibo related to Yoriichi? Are Kokushibo and Yoriichi same person? If you too have several such questions don’t worry I will answer them all today.

So the very first question that arises is,

Is Yoriichi Related To Tanjiro? Is Yoriichi Tanjiro’s Father?

While laying in the hospital recovering from his visually orgasmic fight with upper-rank 6 demons Daki and Gyutaro, Tanjiro has a dream wherein supposedly he or his ancestor met Yoriichi.

In this dream we see Yoriichi talking with Sumiyoshi a person who looks like Tanjiro and has hair similar to Yoriichi and Tanjiro himself. This made many people wonder whether they are family members.

Not to forget Yoriichi is also seen sporting a mark on his head which is similar to Tanjiro’s. This further strengthened the belief that they could be related in some way.

Furthermore, both Yoriichi and Tanjiro use Sun Breathing and also they both wear Hanafuda earrings which are passed down from generation to generation, so they have to be related right?

However, sorry to burst your bubble but Tanjiro and Yoriichi are not related biologically to each other.

Although, this might have hurt you believe me there are various ways in which these two are connected and that is way more awesome than being biologically related.

As it is well known than Yoriichi was the first user of the Sun Breathing technique and the rest of the other users were killed by Muzan.

It makes us wonder how did then Tanjiro’s family know about Sun Breathing? Click the previous text or the link below to know more about that:

As revealed in the first episode of Demon Slayer Season 3 To The Swordsmith Village, Tanjiro’s ancestors Sumiyoshi and his wife were saved by Yoriichi and they become friends later on.

Yoriichi grows fond of the Kamado family and to oblige a request and to show his gratitude he performs all the 13 techniques of the Sun Breathing which Sumiyoshi memorizes instantly.

Also, in the first episode, it is mentioned that Yoriich is disturbed that he couldn’t kill Muzan which cost him the lives of his comrades and his brother and that he doesn’t have any heir.

Sumiyoshi is determined to carry forward the legacy of Yoriichi’s great work and thus passes on all the 13 techniques of Sun Breathing to his next generation as a dance ritual.

Over time, the last step is missed out and until the dance ritual is taught to Tanjiro only the first 12 forms are carried out.

Also, before leaving the Kamado family Yoriichi hands his only heirloom the Hanafuda earrings to Sumiyoshi as a token of thanks which the coal seller also passes down to the next generation.

Isn’t this type of legacy better than being related by blood? At least I think it is.

This shows that Yoriichi left the place to be never seen again by human eyes.

However, many people pointed out that Yoriichi later on joined Muzan by becoming his Upper Moon Rank 1 Demon and changed his name to Kokushibo.

Is that true? Let’s find out:

Is Yoriichi Upper Moon Rank 1 Demon Kokushibo?

Is Yoriichi Upper Rank 1 Demon kokushibo In demon slayer?

Fans have been speculating about this since the previous season.

There are several points which hint at that as well. Points like, them having the same hairstyle.

Similar fashion sense. Both of them are excellent swordsmen and breathing technique users.

But think of it, Yoriichi is so much stronger than Muzan that it gives the Japanese anime version of Michael Jackson PTSD even after almost 1000 years. Then why would he choose to be under Muzan?

Is it immortality that swayed him? Or was it the death of his comrades and the failure of being unable to save his brother that made him rethink his decision of staying a human?

Well, Yoriichi has several reasons to become the thing he hated the most. However, a pure heart doesn’t sway even in the darkest alleys.

So no, Yoriichi is not the upper moon rank 1 demon Kokushibo.

But then who is Kokushibo? Why does he look similar to Yoriichi?

How is Kokushibo The Upper Moon Rank 1 Demon Related To Yoriichi Tsugikuni?

As you know by now that Yoriichi was unable to save his brother. When I said that it was not from death at the hands of demons. Rather it was a failure of being unable to keep his brother away from the darkness of the heart.

Yoriichi had a brother who was an excellent swordsman but not as strong as Yoriichi himself.

The fact that he was weaker than a physically frail Yoriichi made his heart jealous of his own younger brother.

This darkness of heart and several other reasons such as being unable to master Sun Breathing made the older brother turn to Muzan to become stronger than his brother.

Also, since childhood, this brother was the favoured child of the family as Yoriichi and he were twins and the latter was born with a weird scar on his head. Also, twins were considered a bad omen during the Sengoku era.

Due to this their father decided to kill Yoriichi however, their mother intervened and struck a deal that we will raise the boy and send him off to become a priest once he grows up.

Being the favoured child Kokushibo was raised like a prince whereas Yoriichi and his mother were kept separately. This discrimination led Kokushibo to believe that he was better than Yoriichi from a young age.

Kokushibo was also being trained to become a Samurai whereas young Yoriichi was always used to clinging to his mother’s left side which later was revealed to be able to support her due to her ill health.

One day when Kokushibo was training with his teacher, Yoriichi showed interest in learning how to swordfight. The teacher taught him a single stance and started a duel with a child Yoriichi.

Despite knowing only one stance, Yoriichi was able to defeat the teacher thanks to his natural ability to see the Transparent World which was granted by the scar on his head.

This Transparent world ability is like an X-Ray vision where a person can see the other person just as muscles and bones.

Due to this ability, Yoriichi came to be known as a child prodigy and it widened the gap between the brothers.

Knowing that he was stronger than his brother, Yoriichi left to become a priest. Later on, to avoid suspicion and protect the innocent he secretly became a demon slayer.

One day when his brother and his wife and children were attacked by a demon, Yoriichi stepped in to save them.

After seeing his brother had lied to him about becoming a priest and the shame of being saved by him made Yoriichi’s brother more jealous and made him join the ranks of demon slayer by leaving his family behind so that he could catch up to his brother.

But even there he couldn’t master the Sun Breathing this led to him developing another breathing style i.e. Moon Breathing. This breathing style became known as the second-strongest breathing style to ever exist.

Despite being the second strongest it didn’t fulfil his heart. Afraid that he will never be stronger than Yoriichi he went to Muzan seeking more powers and immortality.

At last, after becoming a demon he met his brother in the final battle however before the fight could end and he could land a fatal blow Yoriichi had already died of old age. This enraged him further.

This brother was none other than Kokushibo, Yoriichi Tsugikuni’s twin brother and the current upper moon rank 1 demon.

So yeah, Yoriichi and Kokushibo are brothers and are mortal enemies despite loving each other deeply.


Kokushibo, the upper moon rank 1 demon and Yoriichi are not Tanjiros’ father and neither are Tanjiro’s relatives. However, Kokushibo and Yoriichi are siblings and respect each other a lot despite Kokushibo hating the entirety of his brothers’ being.

These brothers singlehandedly helped (directly and indirectly) Muzan shape the country’s nightlife. They were so strong that they could have ruled the country if they worked together but human emotions are more vicious than any demon lord.

  • Good article.
    But there are only twelve techniques of sunbreathing. The 13th is the Hino Kami kagura itself. When using the 13th, the User performs all 12 techniques Starting with the First and ends with 12th.

    • Exactly! Hence it is the thirteenth form. The user has to perform all the first 12 forms in succession without stopping which makes it the most difficult form to perform and thus it is the strongest.

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