What Is Gyokko’s Human Backstory & Who Turned Him into a Demon?

What is Gyokko's Human Backstory & Who Turned Him into a Demon?

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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 – Gyokko. The Upper-Rank Five of the Twelve Kizuki, Gyokko, was a very intriguing villain with interesting water-based powers. In the most recent episode, we’ve gotten a glimpse of Gyokko’s backstory, which is also going to be the topic of this article. In it, we are going to tell you all about Gyokko’s backstory and will also reveal who turned him into a Demon.

Gyokko was formerly known as Managi, and he lived in a small fishing village with his family. One day, his parents drowned while fishing, and as Managi saw their corpses, he became fascinated with them. He would later examine fish corpses, and when a boy teased him about it, Managi killed him and stuffed him in a fishing pot. When the dead boy’s parents discovered Managi was at fault, they stabbed him with a spear and left him for dead. Before he died, though, Muzan found him and transformed him into a Demon, giving him the name – Gyokko.

The remainder of this article will give you a detailed overview of Gyokko’s story, as it happened on the pages of the Demon Slayer: Kimetsu no Yaiba manga. You already know what happened and how it happened, so we will just bring you the details so you know the whole context. Be careful, though, as the article will contain many spoilers, so if you don’t know all the details, be careful how you approach the text.

Gyokko’s backstory was revealed in the Kimetsu no Yaiba Official Fanbook 2

Like every Demon in the series, Gyokko also has a human backstory. Every Demon was once a human who was, by Muzan or someone else, turned into a Demon at one point in the story. Gyokko is, thus, not an exception, but his backstory was never shown in the manga; in fact, it was first revealed in the Kimetsu no Yaiba Official Fanbook 2, which was released in Japan on February 4th, 2021. In it, Gyokko’s canon backstory was presented, and we are going to tell you that story here in this article.

Gyokko was born as a human boy named Managi to unnamed parents who lived in a small coastal village that mainly lived off fishing; his parents were also fishermen and would often go to work, leaving the young Managi alone.

As far as we’ve seen, Managi was initially a normal child, and there was nothing wrong with him then until tragedy struck him at one point in his childhood. This tragedy would shape him into a foundation for what would later become the Demon Gyokko.


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One day, when he was a child, his parents went out for their usual fishing work, but they never returned. Managi waited, but they never came, and he found out that the two of them had drowned while fishing. No details have been provided, so we don’t know whether it was an incident or an accident or whether someone was at fault. We just know that they drowned and never returned.

After a while, though, their drowned corpses were washed up on the shore, and young Managi saw them, which is also when his fascination with corpses developed. A bit bizarre, but hey… who are we to judge?

Anyhow… Managi’s fascination with corpses was a thing now, and he would constantly walk by the coast to observe the fish corpses, showing visible fascination when facing them. As the villagers observed this strange ritual, they all thought that Managi had gone insane due to the loss of his parents, and they kept their distance, ostracizing the young boy without any apparent reason.

Managi didn’t seem to care, though, as he simply continued observing corpses while not minding the others. While bizarre, his hobby did not bother anyone or cause trouble for the people in the village.

But as these situations usually go, while Managi minded his own business and opted to not bother anyone, people wanted to pick on him, and one day, an unnamed boy picked on him and teased him because of his bizarre fascination. To be honest, something was probably wrong with Managi, as such a fascination at such an age is definitely not normal, but whether what happened next is an overreaction or not… well, we leave it to you, the reader, to judge that for yourself. We’ll just lay out the facts as they happened.

So, while being teased and picked on, Managi snapped at one point and attacked the unnamed boy, killing him in the process. He then took his body and stuffed it inside a pot that was used for fishing, and… well, this is yet another foundation for what is to become Gyokko later on in the story, as you can observe. When he put the body inside, he seemingly returned to normal.

The boy’s parents, of course, raised the alarm and went to search for their son, and when they discovered his body in a pot, they immediately realized it was Managi who had killed him.

Out of anger, the parents then grabbed a spear and struck the young Managi with it, seemingly killing the boy. In any case, the grieving parents left the stabbed boy for dead and left the scene, seemingly without any consequences. But – Managi was not dead. He was dying and bleeding, but he managed to survive for a full 12 hours before being ultimately found by Muzan, who took a liking to him and turned him into a Demon. This is how Gyokko was born, and later on, he would become the Upper-Rank Five of the Twelve Kizuki.

Gyokko was turned into a Demon by Muzan

As you can see, Gyokko was turned into a Demon by Muzan himself, which was a big honor for the newly-nascent Demon. As the Upper-Rank Five of the Twelve Kizuki, Gyokko was an exceptionally powerful Demon that possessed powers and abilities beyond any conventional Demon, being able to rise to the level of the Hashira as seen in his confrontation with Muichirō Tokitō, eventually surpassing him and coming close to killing him during the fight. Still, Muichirō managed to win after awakening his Demon Slayer Mark, despite Gyokko also appearing in his true form.

But, aside from the fact that Gyokko has become a very powerful Demon, there is also something we have to say about his early life as a Demon. These facts have also been revealed only in the Kimetsu no Yaiba Official Fanbook 2, so you won’t find them in the manga, and while they remain unknown to most fans, they are important for understanding how and why Gyokko became what he became and how his Demonic personality developed and evolved after becoming a Demon.

This is why we are going to present these facts to you here.

So, after becoming a Demon, Gyokko developed an unnatural hatred for all living things. Taking into account his fascination with corpses, such a thing makes sense. He despised life and loved death, which was a trait he kept while he was human. This is an interesting fact, as Demons usually lose all their prior memories after the transformation (this is not always the case, but it generally is), but they do seem to retain some personality traits and quirks that they had as humans, although they don’t seem to understand them on a conscious level.

Gyokko also retained his fascination with fish, so much – in fact – that he modified his body so that it resembled a fish. It also explained his fish-themed attacks and skills.

He also had a fascination with pots and developed a liking for grabbing humans and putting them into his pots, where they would die. He also had a morbid habit of turning the corpses into bizarre works of “art,” human sculptures, and while Managi had not shown an artistic side to him, his fascination with corpses probably had an artistic value for the young boy, although he was not advanced enough to express it properly. But, as a Demon, he seemingly managed to do it and was more than brutal and morbid while doing it.


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Ultimately, Gyokko also developed an unhealthy obsession with Muzan, whom he adored fully. He adored Muzan’s presence and would blush all over even when Muzan scolded him and hurt him (he did not like pain in general, like Dōma, but he liked Muzan, so he would tolerate everything coming from him). All of this molded Gyokko into the bizarre monster we saw in the series, and because all of this data was not present in the manga, we wanted to share it with you here.

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