Is Kagaya Ubuyashiki Related To Muzan In Demon Slayer? Explaining Their Connection In Detail


The Finale of Demon Slayer Hashira Training arc had gained quite the commotion animation wise, trending #1 worldwide and crashed Crunchyroll’s site once again. But apart from the animation, there was plenty of lore to discuss. One is the shocking revelation that the Ubuyashiki clan is related to Muzan blood-wise.

That brings us to the following question.

Is Kagaya Ubuyashiki Related To Muzan In Demon Slayer?

Yes. Ubuyashiki, the leader of the Demon Slayer Corps, and his family are indeed connected to Muzan. In fact, Muzan was born in his line and that brought a curse upon the clan. Since then, the clan always hated Muzan, including Kagaya as well.

After all, even Muzan knew that the time for the final showdown had arrived, which is why he went to meet his bitter enemy for ages, Kagaya Ubuyashiki!

His audacity is just out of this world because he casually adds property invasion to his list of crimes by entering Kagaya’s home, but even blindness doesn’t stop him from realizing that his esteemed guest is none other than Muzan.

After asking for a description of Muzan from Amane since this was their first meeting, Kagaya expresses that he had expected the demon to appear. He knew that Muzan’s fury toward his clan would drive him to seek Kagaya out for a personal confrontation.

Muzan confirms this, expressing disgust at the Ubyashikis clan’s endless interference throughout his existence. However, now, he finds their leader in a pathetic state where Kagaya seems loathsome, indescribably ugly, and already possesses the scent of a corpse.

Despite this insult, Kagaya actually agrees with Muzan because, 6 months ago, his doctor said he only had a few days to live. The only reason he’s still alive now is because he’s determined to defeat Muzan, but the demon simply states that all his efforts will be useless when he kills him.

Since Muzan was born so long ago, he wouldn’t have known the fact that he shares the same ancestors as Kagaya. So, he further explains that Muzan is the reason for his family’s curse.

Well, the Ubuyashiki clan was cursed so that its children would be weak and die young, all because they had to bear a monster like him. All the future generations had to bear the sin of Muzan’s existence, as he was an unnatural entity who should’ve died before even being born.

With so many descendants dying because of the curse, the clan faced the threat of extinction. This was when a priest approached them, explaining that since a demon was born in their bloodline, they had to repent in order to save their bloodline.

The solution was to dedicate themselves to killing the demon so that the clan could survive. Moreover, Kagaya reveals that he married Amane because her family was brought up in the priesthood. Despite following the priest’s advice, the Ubuyashikis lived only slightly longer because none had lived past the age of 30.

However, Muzan doesn’t believe in Kagaya’s story at all, wondering if his sickness has affected his brain. He argues that his past is irrelevant to the present and claims that despite killing thousands of people, the heavens have never punished him. He also adds that in his thousand-year existence, he has never seen evidence of the gods or Buddha.

To know more about him, Kagaya then questions Muzan about his dreams and lifelong desires, as the demon thinks about how, even facing the leader of the Demon Slayer Corps, he feels no hatred.

But as he observes Nichika and Hinaki playing happily in the Ubuyashiki mansion, he experiences a strange sense of familiarity mixed with relief and disgust. This tells us that Kagaya’s tale is true, and Muzan feels these dual emotions because he was a human once, but now he’s a demon. Hence, Kagaya offers an answer on his behalf: eternity and immortality.

The demon agrees, stating his plan to achieve this by finding Nezuko, but Kagaya refuses his success because the only eternal thing is human feelings.

According to him, what Muzan dismisses as nonsense is, in fact, proof of the enduring nature of human emotions. The refusal to forgive those who unjustly take lives. Kagaya warns Muzan that, by metaphorically stepping on the tiger’s tail, he has awakened the dragon’s wrath. He further taunts Muzan for failing to grasp human feelings, noting that if Muzan dies, all demons will perish.

Finally, Kagaya also adds that while his own death may be meaningless, it is not insignificant. Since the Demon Slayer Corps and the Hashira hold him in high regard, his death would only serve to motivate them further.

All of this angers Muzan, and he instantly kills Kagaya, marking yet another sacrifice from the Ubuyashiki clan as well as the end of the last head of Demon Slayer Corps at age 23. He was a leader that the Hashiras truly respected and admired because, even when he became immobile and bedridden, Kagaya never missed a day visiting the graves of the fallen Demon Slayer Corps members until the day he was no longer able to do so.