Kagaya Ubuyashi is easily the most underrated Demon Slayer character among most fans. As the leader of the Demon Slayer Corps, he was loved by everyone in the organization. However, people didn’t respect him because of his title, but rather they admired his personality, kindness, and the ability to soothe anyone’s soul with his calming voice. However, because of the curse put on his bloodline for sharing the same blood as Muzan Kibutsuji, Kagaya was doomed to die young. He always had a frail body, but still cared deeply for the Corps members, even after he couldn’t even move anymore. Because of the curse his family was forced to carry for over a thousand years, Kagaya held deep resentment towards the demon progenitor.
Videos by ComicBook.com
No one could’ve figured out the animosity his kind face was showing. Even after facing Muzan in the Hashira Training Arc finale in the anime, Kagaya was able to converse with the villain with exceptional calmness. What’s truly surprising is that not even Muzan could bring himself to hate the frail and sickly man in front of him, despite being mortal enemies. However, what Kagaya did next shocked the demon to his very core, something he never would’ve anticipated. Kagaya blew up the Ubuyashiki manor, taking his life along with his wife and two daughters. This act triggered the final battle against the demons.
Kagaya’s Voice Actor Shares Thoughts on the Best Demon Slayer Anime Scene

In an interview with Oricon, Kagaya’s voice actor, Toshiyuki Morikawa, shares his experience working on the anime. In the anime, before blowing the mansion, Kagaya said to Muzan, “Eternity lies in human emotions. Human emotions are what make us eternal and indestructible.” The interviewer asked Morikawa about this scene and how he perceived the character as well as the series. Morikawa replied, “I believe this line captures the essence of the work. The fact that Oyakata-sama (Master or Lord) speaks these words to Muzan holds great significance.”
He continued, “The greatest appeal of this work lies in human emotions. It portrays intangible aspects such as feelings towards life, family, and friends, and focuses on these elements. I believe this is what makes Demon Slayer so compelling. Indeed, human emotions are eternal and indestructible.”

After coming face-to-face with Muzan, Kagaya knew that the one thing the demon wanted was eternity. The demon had been around for over a thousand years, but he could only be free when he could walk under the sun. Kagaya had a different perspective from Muzan on what eternity means. He placed great value on humans, including the Corps members, whom he always referred to as his children.
Kagaya believed that humans’ greatest strength is eternity, not a never-ending life, but the ability to feel emotions as well as being able to remember those who have departed. The manga also highlighted how he would visit the graves of the deceased Demon Slayers every day until his condition became so critical that he couldn’t get up from bed.
Demon Slayer: Infinity Castle is the result of his actions and unwavering resolve to see the end of demons in his generation. The first part of the trilogy film was released on July 18th, 2025, but only in Japanese theaters. The film will hit the U.S. theaters on September 12th, 2025, and tickets will be available starting August 15th.
H/T: Oricon