Did You Know?
- The word 'oni' (鬼) originally referred to invisible spirits that caused disease and disaster. They only gained their iconic horned, club-wielding form during the Heian period (794–1185), borrowing visual elements from Chinese devils and Buddhist imagery of hell's guardians.
- Setsubun — Japan's bean-throwing festival — involves shouting 'Oni wa soto!' (Demons out!) while throwing soybeans to drive oni from the home. The tradition dates to at least the 8th century and is still observed on February 3rd.
- Shuten-dōji, the most famous oni in Japanese folklore, was said to be over 15 feet tall, able to consume a human body in one bite, and was eventually defeated by the legendary warrior Minamoto no Raikō through deception rather than force.
This oni name generator produces Japanese-style names for demon-ogres by type (red, blue, black, fallen human, lord, shaman) and role, and the 42 real names below show what the genuine article looks like. Where our yokai names page covers the whole spirit world, this one stays with oni: the horned figures of legend, hell's wardens, and the demons of modern anime.
Oni of Legend and Buddhist Hell
| Shuten-dōji | Leader of the oni on Mount Ōe; in the legend Minamoto no Raikō beheads him after he drinks poisoned sake |
| Ibaraki-dōji | Shuten-dōji's most important subordinate; Watanabe no Tsuna cuts off his arm in the Rashōmon tale |
| Ōtakemaru | Named with Shuten-dōji and Tamamo-no-Mae as one of the three most feared yōkai of medieval Kyoto |
| Gozu (牛頭) | "Ox head"; underworld warden who escorts the dead to judgment |
| Mezu (馬頭) | "Horse head"; Gozu's counterpart among the hell wardens under King Yama |
| Nio (仁王) | Wrathful Buddhist guardian figures at temple gates, linked to oni imagery |
Oni Types, Words and Epithets
These are descriptive labels rather than personal names. They work as the second half of a compound, such as a colour or a title.
| Aka-oni (赤鬼) | "Red oni"; the red-skinned type |
| Ao-oni (青鬼) | "Blue oni"; the blue-skinned partner of the red type |
| Oni (鬼) | Base word; in Japanese "ghost, spirit, demon", and the root of most compound names |
| Oni wa soto | "Oni outside!"; the Setsubun bean-throwing cry, a ready-made epithet |
Demon Names From Demon Slayer
Most readers searching for Japanese demon names have this series in mind. The list gives each demon's rank or role and, where the series states it, the human name behind the demon. For more from the franchise see Demon Slayer names.
| Muzan Kibutsuji | The progenitor of all demons and the series' main antagonist |
| Kokushibō | Upper Rank One; formerly a Demon Slayer named Michikatsu Tsugikuni |
| Michikatsu Tsugikuni | Kokushibō's human name |
| Doma | Upper Rank Two; founded a religious cult |
| Akaza | Upper Rank Three; formerly a teenager named Hakuji |
| Hakuji | Akaza's human name |
| Hantengu | Upper Rank Four; splits into emotion-based clones |
| Sekido | One of Hantengu's clones |
| Karaku | One of Hantengu's clones |
| Aizetsu | One of Hantengu's clones |
| Urogi | One of Hantengu's clones |
| Zohakuten | One of Hantengu's clones |
| Urami | One of Hantengu's clones |
| Gyokko | Upper Rank Five; claims to be an artist |
| Daki | Upper Rank Six, shared with her brother; an oiran in the red-light district |
| Gyūtarō | Upper Rank Six, shared with Daki; a debt collector |
| Kaigaku | Successor to Upper Rank Six |
| Enmu | Lower Rank One; manipulates dreams |
| Rui | Lower Rank Five; builds replacement families |
| Kyōgai | Lower Rank Six, the drum demon |
| Kamanue | Lower-rank demon, eliminated by Muzan |
| Mukago | Lower-rank demon, eliminated by Muzan |
| Wakuraba | Lower-rank demon, eliminated by Muzan |
| Rokuro | Lower-rank demon, eliminated by Muzan |
| Nakime | Biwa-playing demon who owns the Infinity Castle |
| Tamayo | Doctor demon who broke free of Muzan's control |
| Yushirō | Tamayo's devoted creation |
| Nezuko | Protagonist's sister; a demon who keeps some human cognition |
| Susamaru | Minor demon in the series |
| Yahaba | Minor demon in the series |
How Oni Names Are Built
Ibaraki-dōji means "Ibaraki child": a place name plus dōji, the ending Shuten-dōji shares. That gives a simple recipe: a place or trait, then a title.
The Demon Slayer list shows the second recipe. Kokushibō and Akaza each keep a human name from before the transformation, and that gap between the two names is what makes them tragic. If you write a fallen human, give your character both.
What the Generator Is Built to Do
The generator keeps the conventions a reader of Japanese would expect. Long vowels carry macrons (Hyōga, not Hyoga), title suffixes such as -maru, -ō and -dōji attach to the root with no space, and compound epithets take hyphens, as in Shuten-dōji. A default batch of five mixes two suffixed names, two hyphenated compounds and one short root.
Pick a type to steer the sound. Red oni names lean on hard consonants and fire or iron imagery, blue oni names on cooler water and ice words, and ancient lords on titled compounds. Tone and starting letter narrow it further.
Skip These
Names that only sound Japanese. A string like "Takami" says nothing about oni.
Every antagonist ending in -maru. The ending is common enough that a cast of five reads as a template.
Common Questions
What is a good Japanese demon name for a male character?
Start from the legend names in the first table: Shuten-dōji, Ibaraki-dōji or Ōtakemaru. For an original name, run the generator on the Ancient Oni Lord or Berserker setting and keep the -dōji or -maru ending.
What do red and blue oni mean?
Aka-oni is "red oni" and Ao-oni is "blue oni", the two colour types. In folktales the red oni is sometimes shown seeking human friendship, as in the story of the red oni who cried.
What does the word oni mean?
In Japanese, 鬼 means ghost, spirit or demon. Today it names the horned, club-carrying ogre, and it also appears in compounds such as 赤鬼 and 青鬼.
Is a tengu the same as an oni?
No. Both are yōkai, but they are separate creatures with separate naming habits. See tengu names for that tradition.
Sources
Updated October 2026: replaced invented example names with 42 attested legend and Demon Slayer names, added sources and revised FAQs.
