"[Demon Slayer Analysis] What are 'Oni'? Exploring the True Identity of Japan's Ancient 'Oni' with the 'Dictionary of Oriental Deities'."

Hello! This is Osamu, the manga blogger.

Demon Slayer has taken all of Japan by storm. Its appeal, of course, lies in its moving story and fascinating characters. But I believe the root of its horror—and its sorrow—lies in the existence of the "Oni" (demons).

They are depicted as transcendent beings who rule the night, devour humans, and possess incredible regenerative abilities.

So, are these "Oni" in Demon Slayer the same as the "Oni" we know from classic folktales (like Momotaro)?

Today, with my copy of the Dictionary of Oriental Deities in hand, I want to do a deep-dive analysis into what the "Oni" of Demon Slayer really are and explore their roots!

First off, what is an "Oni"?

Let's first define the Oni in Demon Slayer.

They are beings created by the blood of the progenitor, Kibutsuji Muzan. They prey on humans and cannot be killed by anything other than sunlight or a "Nichirin Sword."

On the other hand, when you look up the ancient Japanese "Oni" in sources like the Dictionary of Oriental Deities, you find something very interesting.

There are many theories about the etymology of the word "Oni," but a prominent one is that it's a corruption of the word "On" (隠), meaning "hidden" or "concealed."

In other words, they originally referred to "things that cannot be seen" or "things not of this world"—the very "unidentifiable, terrifying presence" that brought natural disasters and plagues.

This is a bit different from the image of the Demon Slayer Oni, who have physical forms and were originally human, isn't it?

Was the Image of the Oni "Imported"?

So, where did our familiar image of the Oni—"with horns, a tiger-skin loincloth, and an iron club"—come from?

Actually, this image was born from a fusion of various concepts from Chinese and Indian mythology and Buddhism as they were transmitted to Japan.

Looking at the Dictionary of Oriental Deities, I found beings that seem to be their roots.

1. The Man-Eating Demon "Rasetsu" (Rākṣasa)

According to the Dictionary of Oriental Deities, "Rasetsu" (Rākṣasa) are fiends or demons originating from Indian mythology.

They were incorporated into Buddhism and are sometimes depicted as the jailers (Gokusotsu) of hell, but their most terrifying trait is that they "eat people."

This absolute rule of the Demon Slayer Oni—that they "prey on humans"—don't you think this is more strongly inherited from the "Rasetsu" of Buddhism (Hinduism) than from the ancient Japanese "On"?

2. The Powerful "Yasha" (Yākṣa)

Also appearing in the Dictionary of Oriental Deities is the "Yasha" (Yākṣa).

This is another demon god from Indian mythology. While sometimes seen as a guardian deity in Buddhism, it also has an extremely powerful and ferocious side.

The supernatural "Blood Demon Arts" and the overwhelming physical abilities shown by the Demon Slayer Oni, especially the "Twelve Kizuki" (Twelve Demon Moons)...

I believe this image of "power beyond human comprehension" is strongly influenced by these Buddhist demon gods, like the "Yasha" or perhaps "Gozu" (Ox-Head) and "Mezu" (Horse-Face), who are said to torture the dead in hell.

The Demon Slayer Oni is a Mythological Hybrid

When you analyze it this way, you can see just how skillfully the "Oni" in Demon Slayer were created.

1. The ancient Japanese "Oni" (On): The aspect of "unseen terror" that lurks in the night and attacks people unseen.

2. The Buddhist "Rasetsu" (Rākṣasa): The grotesque habit of preying on humans.

3. The Buddhist "Yasha" (Yākṣa): The terror of possessing supernatural abilities (Blood Demon Arts) that surpass human understanding.

By fusing these mythological "Oni" images from all times and places, and then adding modern (almost vampiric) settings like "perishes in sunlight" and "multiplies through blood," the one-and-only "Oni of Demon Slayer" was born.

Kibutsuji Muzan, who was born in the Heian period, took the ancient Japanese concept of "Oni" and incorporated the characteristics of "Rasetsu" and "Yasha" from the continent, undergoing his own unique evolution... When you think of it like that, you can enjoy the story on an even deeper level, can't you?

Why don't you all try thinking about which mythological elements your favorite Oni possesses?

Well, see you on the next blog!

This was Osamu.