Gyutaro was an enigmatic figure in Demon Slayer. The primary antagonist of the Entertainment District Arc, Gyutaro was an upper rank 6 demon along with his twin sister Daki. Upon his introduction, Gyutaro seemed to be merely a twisted, sick, sadistic being. And surely, he is all of that and more. However, as his story unfolds, we come to learn, that there is more to Gyutaro than meets the eye.
Gyutaro was born into a poor family in the Entertainment District. His mother would frequently beat and attempt to murder him even before he was born, ostensibly owing to an attempted miscarriage since she couldn't afford to feed him, but her efforts were in vain when she died of syphilis.
Throughout his boyhood, the other residents of the district chastised him for his appearance, voice, and lack of hygiene. Unwanted, uncared for and unloved, Gyutaro lived a lonesome existence. As cruelty begets cruelty, the young boy began to harbour feelings of envy and resentment towards others, especially the rich and the pretty.
Daki and Gyutaro
Gyutaro was filled with pride and joy when his younger sister Ume (later known as Daki) was born. Ume was everything he wasn’t, pretty, elegant and above all, sought after. In the Entertainment District, beauty was the only value a person could have and Ume was a treasure trove at that.
He acted as Ume’s “collector” in the district and he was brutal. Life was good for the siblings for a brief window of time. They had their struggles but Gyutaru deeply cared for his sister, trying to provide for her and protect her in all circumstances. However, all good things must come to an end.
End of Gyutaro’s Humanity
One day, after Ume turned 13, she stabbed a samurai in the eye who was trying to have his way with her. When Gyutaro went home from work one day, he discovered his sister bound and burned to near death, abandoned in a ditch. He jumped into the ditch and began to panic, crying and hugging his sister's body as he pleaded that she be returned to normal.
The same samurai who blinded Gyutaro reappears and slashes his back in an attempt to kill him as he embraces his dying sister. The samurai had conspired with the siblings’ manager to kill Gyutaro. However, before the samurai can finish him off, Gyutaro jumps out of the ditch and uses his sickle to kill both the manager and the samurai.
Despite his injuries, Gyutaro carried his sister Ume's dying body throughout the Hanamachi district in quest of assistance, but he was eventually confronted with the harsh reality that no one would help them no matter where he went. Both he and Ume were on the edge of death when he succumbed to weariness. They were eventually discovered by the then-Upper Rank Six Doma, who was prowling the Entertainment Districts for young women to consume.
He then volunteered to "help" them by transforming them into demons because he was a "Nice Guy". To that end, he gave them a few drops of his blood to begin the process. He then exhorted them to become great enough to be picked by "that man" and join the Twelve Kizuki.
Life as Demon
Gyutaro and his sister, who was now known as "Daki", began to torture and feast on the residents of the Entertainment District as demons. The siblings apparently developed a liking for only eating from the district's finest and most attractive geisha and oiran. The siblings were finally seen and acknowledged by "that man" and awarded the position of Upper Rank 6 of the Twelve Kizuki, which they then shared among themselves, after an unknown amount of years.
Gyutaro killed and ate at least fifteen Hashira of the Demon Slayer Corps during his long life as a demon, while his sister killed and ate seven.
Death of Gyutaro
Gyutaro was killed by Tanjiro at the end of a very fierce battle. At the same time, Daki was decapitated by the combined efforts of Inosuke and Zenitsu. As the dying siblings lay next to each other in their final moments, they began to bicker. Gyutaro loses his cool and starts making cruel remarks about how his life would have been better without her and how he wishes she had never been born, which causes Daki's eyes to well up with tears. Tanjiro steps in and covers Gyutaro's mouth, telling him that they shouldn't waste their last minutes fighting.
Out of frustration, Daki begins to howl at Tanjiro, yelling at him to leave them alone. Daki's head is disintegrating to the point where she begs out for her brother to save her, stating she doesn't want to die. Gyutaro looks helplessly as her head fades away while still reaching out to him, before impulsively addressing her by her given name, Ume, a name he had forgotten.
It is difficult to sympathize with the demon siblings considering the sheer cruelty and consequences of their deeds. However, in their final moments, the two showed their long lost humanity within them in a tragic sequence of events. One can not help but wonder, if the circumstances were different, wouldn't the siblings have lived and died a normal, mundane and happy human life?