The Demons of Demon Slayer are a truly fascinating lot. They come in all shapes and sizes, and while they are evil in their demonic form, their backstories and their lives while they were human usually contain a tragic note that makes you sad for them. But there are also exceptions, and one such exception is the protagonist of this article – Kokushibō. The Upper-Rank One of the Twelve Kizuki, Kokushibō was the second strongest Demon in the lore, behind only Muzan. And while this article will not focus on these aspects, it will still be dedicated to Kokushibō and one aspect of his story. Namely, in this article, you will find out whether Kokushibō is a hybrid half-demon in Demon Slayer.
Kokushibō is not a Hybrid/Half-Demon in Demon Slayer; he was born as a human and way transformed into a full and proper Demon by Muzan, so he is now a Demon. Also, officially, there are no Hybrids/Half-Demons in Demon Slayer (as Nezuko is still considered to be a Demon), as this is a fan-made concept, which means that Kokushibō cannot even be one.
In the rest of this article, we will tell you what you need to know about the issue of Kokushibō and his heritage and what we know about it, at least. We now know the reasons behind his monstrous transformation, but we will also explain all the relevant details you need to know. If you’re not fully up to date with Demon Slayer, there might be some spoilers ahead.
Kokushibō was a man called Michikatsu Tsugikuni before becoming a Demon
Kokushibō was introduced to the series as Muzan’s Upper-Rank One, the most powerful member of his demonic Twelve Kizuki. And while that confirmed that he was a Demon, fans who explored his history a bit found out that he has quite a complex story behind him, so they started wondering whether he could be a Hybrid or a Half-Demon, as the concept is also called.
But, before we actually bring you Kokushibō’s story, we’ll just quickly confirm that he is not a Hybrid/Half-Demon, as the concept doesn’t even exist in the Demon Slayer lore, which is also something we are going to elaborate on later in the article. Now, let us see Kokushibō’s story.
Kokushibō was born as Michikatsu Tsugikuni, the older twin of Yoriichi Tsugikuni, in a period when twins were regarded as bad omen. Yoriichi’s father threatened to kill Yoriichi because of a peculiar birthmark on his son’s forehead, but their mother, Akeno, became enraged and detained him. It was ultimately decided that Yoriichi would be sent to a temple at the age of ten to become a monk.
When their mother passed away when Yoriichi was ten, Yoriichi visited Michikatsu and told him he was leaving the family as was arranged. He thanked his brother, told him he would always keep thinking of him, and took a small wooden flute Michikatsu had given him earlier as a memory.
He then left; Michikatsu would later find out, through his mother’s diary, that Yoriichi knew all about their mother’s illness and that he helped her, but also that he knew that their father planned on making Yoriichi his heir and sending Michikatsu to a temple, which is why he ran away to spare him. Despite these acts of kindness, Michikatsu still hated and envied Yoriichi, which would prove to be a stepping stone in their relationship later on.
While Yoriichi was leading his own life, Michikatsu met an unnamed woman, fell in love with her, and they had two unnamed children. At the same time, he also worked as a samurai. One night, a Demon attacked his group, and Michikatsu ended up as the group’s only survivor; the issue here was that Yoriichi arrived to save his life, which infuriated Michikatsu, as Yoriichi once again proved to be better than him. Because of that morbid rivalry, Michikatsu left his family and went with his brother to become a Demon Slayer, only to prove that he could be better than him.
But even in the organization, Yoriichi was better. While both of them became Hashira, Michikatsu’s Moon Breathing was only a failed attempt at learning Yoriichi’s Sun Breathing, the first and most powerful Breathing Style. On top of that, Yoriichi was exceptionally strong and considered the most powerful Demon Slayer at the time, which made Michikatsu furious. On top of that, since he had activated his Demon Slayer Mark, Michikatsu was aware that, according to the supposed curse, he would die at the age of 25.
After Yoriichi’s failure to kill Muzan, Michikatsu decided to become stronger than Yoriichi and avoid death by the Demon Slayer Mark’s supposed curse, which is why he accepted Muzan’s proposal and became a Demon, betraying the Corps – he killed the Oyakata and deflected. From that moment on, Michikatsu Tsugikuni was dead, and the Demon Kokushibō appeared. So no, Kokushibō was never a Hybrid or anything similar – he was born a human and then transformed into a full and proper Demon by Muzan.
We also have to add that the concept of a Hybrid or Half-Demon, as it is also called, is unknown in the Demon Slayer canon. It is a theoretical concept devised by fans, and while it is imaginable, we are not sure how it would work in the series, as the author never really pondered on the concept. Nezuko, whom many consider to be a Half-Demon, is still a Demon canonically, and she is considered to be one by the characters.
She resisted her demonic urges thanks to Urokodaki’s conditioning, but that was mostly it. She is not a Half-Demon or anything like that; she was just special enough as a protagonist, which is why she could resist her demonic urges and be a normal character for most of the story until she officially reverted back to her human form. So no, Kokushibō is not a Hybrid/Half-Demon, as the concept does not exist, but he would still not be one even if it did.