Demon Slayer: What was Muzan like as a human? Explained

Taking a closer look into Muzan
Taking a closer look into Muzan's character in the Demon Slayer series (Image via Ufotable)

Kibutsui Muzan, the antagonist of the Demon Slayer series has made a good name for himself; the fanbase has strong opinions of this character and rightfully so. He has committed the most heinous crimes and is single-handedly responsible for terrorizing the entire country of Japan. He also became the first-ever demon in existence and managed to create more of them during his lifetime.

Those who have watched the anime only know a mere speck of his abilities, as the current story arcs have not revealed his powers. However, there is another interesting stream of thought that arises while watching the anime.

Every single demon in the series was a human being at a certain point in time, but what was Muzan like when he was a human being? The answer can be found by looking into the source material, the Demon Slayer manga.

Disclaimer: This article contains massive spoilers from the Demon Slayer manga chapters.


Taking a look at the Demon Slayer manga to understand what Muzan was like as a human being

As a human being, Kibutsuji Muzan wasn’t all that different from what he is as a demon. Ever since he was in his mother’s womb, he struggled to survive. He was born with an extremely frail body in the Heian era. A doctor, hence, was giving him a special prototype medicine, hoping to cure the young boy.

“Desperation to live” is the very core of this antagonist's being; he could do anything to survive, even if it meant taking someone else’s life in the process. The medicine seemed to have deteriorated Muzan's condition; he was incredibly impatient and ended up killing the doctor in a fit of rage.

Soon, he realized that the medicine was in fact working since he ended up becoming incredibly strong and durable. However, he had to do two things to sustain his new body - consume human flesh and not be exposed to sunlight. Even when he was a human in the Demon Slayer series, he didn’t care about the people around him and went to great lengths for his personal well-being.


How old was Muzan when he became a demon?

How old was Muzan when he became a demon? (Image via Ufotable)
How old was Muzan when he became a demon? (Image via Ufotable)

In the Demon Slayer manga, Muzan was diagnosed with a disease that would kill him before he was 20. Since that is the case, it is highly possible that Muzan killed the doctor and turned into a demon when he was around 18-19 years old. It was the survival desperation that drove Muzan insane and made him kill the doctor.

However, all hopes were not lost as he had to just find a plant that would solve all his problems. He was in search of a plant called Blue Spider Lily, which would help him conquer the sun. It was for this reason that he created demons, who were asked to scour the country and find the plant.


Who was the first demon Muzan created?

Tamayo and Muzan's conversation giving us context with regards to her past (Image via Shueisha/Koyoharu Gotouge)
Tamayo and Muzan's conversation giving us context with regards to her past (Image via Shueisha/Koyoharu Gotouge)

The manga didn’t seem to provide information regarding the first-ever demon that Muzan created. However, we know the first notable demon that came into existence after him, who was none other than Lady Tamayo. Her existence was threatened by a fatal disease. She wanted to see her children grow up, and requested Muzan to neutralize it, hence turning into a demon.

But, she couldn’t hold herself back and ended up killing her own family in order to survive as a demon. Since then, she did everything she could to kill Muzan. Ultimately, it was her and Shinobu’s efforts that played a pivotal role in killing Muzan in the Demon Slayer series.


Readers will find more details about Demon Slayer episode 10 here. Be sure to follow for more anime updates and manga news as 2023 progresses.

This article was modified on Friday, June 23 at 17:51 AM.