What is INMU?

Table of contents

1. What do "Inmu" and "INMU" refer to?
2. Started in 2001. However, "memes" came later
3. Who is Yajū Senpai? Why did you become the central character?
4. What is Inmu meme quotes?
5. It's not just videos. Typical secondary creation format created by Inmu
6. How popular was it
7. Why has it become so popular?
8. Why hasn't it disappeared for over 20 years
9. Is it popular overseas too?
10. Why is it compatible with Chinese-speaking countries
11. Are Inmu and LGBT/homosexual culture the same thing?
12. Distinguish between real people and internet memes
13. Relationship with INMU KING
14. Frequently asked questions
15. Summary
16. Main reference materials

What do “Inmu” and “INMU” refer to?

In a narrower sense, it refers to the adult video work ``BABYLON STAGE 34 Midsummer Night's Dream the IMP'' released by Court Corporation in 2001. In a 2014 article by ASCII.jp that analyzed data from Niconico Douga, the tag ``Midsummer Night's Lewd Dream'' is explained as a group of videos that originate from this work.

However, the meaning has expanded greatly on the internet. In addition to the original work, performers from related works, cut-out dialogue, audio materials, BB materials, MAD, live broadcasts, collage images, promises in comments, etc. are sometimes collectively referred to as "Inmu."

"INMU" is the Romanization for "inmu". It is used when searching and tagging with alphabetical characters, and when incorporating it into proper nouns, such as the title of the work "INMU KING." In Chinese-speaking countries, it is sometimes abbreviated to "inm", and this notation is also used in explanatory articles on Bilibili.

It started in 2001. However, "memes" came later.

The original work was released in 2001. However, the current "inmu culture" was not completed at the time of its release. At first, it was just a work for adults.

A 2014 article on ASCII.jp introduces that the work was known before Nico Nico Douga and that the main video was republished on the service in 2007. It has been used in audio MADs since around 2008, and the number of related videos posted has increased since around 2010.

Who is Yajū Senpai? Why did you become the central character?

"Yajū Senpai" is a popular name given to the performers who appear in some of the original works on the internet. He is one of the most famous figures in current Inmu culture, and a large number of derivative works have been created including his face, voice, movements, lines, numbers, and derived characters.

According to ASCII.jp's 2014 tally, it was confirmed that as the number of Inmu-related posts increased rapidly from 2010 to 2011, the center of popularity of posts shifted from the early ``TDN'' to ``Yajū Senpai.'' Since then, formats have expanded, such as the ``BB Senpai Series'' and ``BB Senpai Theater,'' in which characters are freely rearranged as materials.

What is Inmu Kagouroku?

The fixed phrases born from the original video and related works' lines, mishearings, and comment culture are called "inmu words." What is important is that these are not just quotations, but are used by changing the endings, extracting parts of them, or mixing them into other sentences.

Not only short phrases such as "I'll do it" and "It's good," but also numbers such as "114514" and "810," alphabetical abbreviations, and unique phrases are shared across the same cultural sphere. As a result, even if the person himself intended to write normal Japanese, it may end up looking like a memorandum.

This site's meme quote checker takes advantage of the phenomenon of ``looks like a word list without realizing it.''

It's not just videos. Typical secondary creation format created by Inmu

Sound MAD

This is a format in which voices and lines are chopped up, pitch and rhythm are processed, and then incorporated into a song. It was easy to create a song using just the sound, even if you didn't know the visuals, and the short vocal material was reused many times in songs in other genres.

BB Senpai Series / BB Senpai Theater

It is a culture in which people are turned into blue or green backgrounds and distributed as materials that can be composited into other backgrounds. ASCII.jp explains that the ``BB Senpai Theater'' has been established to create original stories such as daily life, horror, and battle from these materials. This is a typical example of characters starting to move independently from the plot of the original work.

Lewd dream commentary

This is a format that incorporates transcripts, images, and sound effects into the game commentary. It is said to have increased since around 2013, and even games that had nothing to do with the original adult video have been incorporated into the erotic dream culture format.

Comment-based formats such as “Learning with homosexuals”

Ordinary educational videos and documentaries have been tagged as Inmu, and the overlapping of viewer comments has created a format in which they can be viewed in a completely different way. ASCII.jp introduces the fact that it becomes a Inmu video by adding comments rather than the video itself, which is a unique feature of Nico Nico Douga.

New theory/Cola/Derivative characters

New theories that link a person's appearance to other objects or characters, collages that use only part of an image, and derivative works that give completely different settings have also continued for a long time. At this point, you don't even need to know the original story. The culture has become such that you can participate if you only know the shape of the material and the promise.

how popular was it

Inmu was a major presence on Niconico in the early 2010s. ASCII.jp counted around 24,000 playable videos under the Manatsu no Yo no Inmu tag in March 2014, with over 1,000 uploads in February alone. Around April 2012, the tag's page views overtook the Games tag; by late 2013, it regularly appeared near the top of the tag trends.

These numbers are from 2014 and do not represent the current number of posts or popularity. The article also mentions the possibility that deletions, tag changes, manipulation of playback numbers, etc. could affect the tally.

Why has it become so popular?

Let's consider the reason why Inmu spread from the ease of use of the meme quotes and the mechanism of secondary creation. The following is an analysis of our site based on publicly available data.

1. Lines are short and easy to mix into everyday conversation

Most vocabulary entries are completed in a few to ten or more characters. You can paste it in a comment as is, or you can mix it into a normal conversation by changing just the ending. Even if you don't have time to watch the video, you can participate with just one word, so the entry point to the meme is very low.

2. High degree of freedom in rearranging materials

The units that can be used are divided into details such as voice, face, expression, pose, numbers, subtitles, and cutouts. It can be ported to other formats according to the production technology of the time, such as audio MAD, collage, BB theater, live commentary, MMD, 3D, AI video, etc.

3. It's not a "completed work" but everyone can increase the settings

Normal works have official settings, but in Inmu's derivative works, internet users have increased their own settings, names, and relationships. Every time a new story is created, it is connected to past stories. This ``worldview that allows for collaborative expansion'' has extended its lifespan.

4. Extremely compatible with Nico Nico Douga's comment culture

Even if it's just a video, it might be a normal video, but if a large number of specific comments flow, it turns into a different content. “Learning with Homo” introduced by ASCII.jp is a perfect example of this. Viewers themselves become part of the work, and the flow of comments changes no matter how many times they watch the same video.

5. The original story and the meme have separated.

The strength of long-lived memes is that you don't need to have seen the original work to use them. Fragments such as just the number "114514", only a specific face, and only the ending of a word are circulated independently. Even when the original work becomes obsolete, fragments can survive in other contexts.

6. The difference between taboo and nonsense

It is originally a work for adults, and the subject matter is people. On the other hand, the derivative works that take place on the internet range from extremely silly wordplays and miscellaneous collages to advanced sound MAD. This strong gap itself is thought to have made it easier to remember as an inside joke.

7. “We can make it again” every time a new technology comes out

Image editing, sound MAD, MMD, game commentary, short videos, and generation AI. Whenever the production environment changes, the same material can be recreated in a new way. “INMU KING” in 2026 can be seen as one of its latest forms.

Why hasn't it disappeared for over 20 years?

One reason Inmu has lasted so long is that it has become a whole set of online vocabulary, reusable footage, editing techniques and comment styles, rather than just one joke.

If it's just one buzzword, people will get tired of it. However, Inmu has a large number of characters, sayings, numbers, audio, MAD format, live commentary format, new theories, and derivative works. Even if some of the material becomes outdated, others will be rediscovered. New users may enter from ``Yajū Senpai,'' or they may arrive at the original culture from fragments such as ``114514,'' ``Yarimasunee,'' and ``INMU KING.''

Is it popular overseas too?

It has also been introduced in English-speaking meme dictionaries and Chinese-speaking video sites. However, we have not been able to find any materials that allow comparison of popularity across countries and regions.

English-speaking countries: Published in meme encyclopedias from quite early on.

The English-speaking meme encyclopedia ``Know Your Meme'' has an entry for ``A Midsummer Night's Lewd Dream,'' which explains characters and derivatives such as ``Yajuu Senpai'' and ``YJSNPI'' in English. Derived items such as "Cyclops Senpai" also exist.

In the English-speaking world, there is also an entry in the meme encyclopedia that introduces Inmu.

Chinese-speaking countries: Commentary and derivative works on Bilibili

In Chinese-speaking countries, spellings such as ``ノ兽前辈'', ``114514'', and ``inm'' are used. Bilibili also has videos and articles that explain the origin, and you can see examples of how Japanese words and numbers are used in other languages. Because the number of views fluctuates, it is not treated as an indicator of popularity.

The 2021 Bilibili commentary article systematically explains in Chinese the sound MAD/derivative creations, 114514, 810, Meryoku Senpai, etc. that came in from Japan's Nico Nico Douga. In addition to direct translations of the Japanese vocabulary, they have also developed unique Chinese paraphrases and a sense of "realistic" language, so they are no longer just imported material.

Weekly Joshi PRIME in 2025 also reports that Yajū Senpai's popularity is expanding in China and Taiwan, and that there was a time when a large number of related thumbnails were seen on Bilibili.

Taiwan: Some cases even went beyond the internet

Related memes can also be found in Taiwan. In 2026, a photo of an image of Yajū Senpai pasted near the driver's seat of a bus in Taipei was picked up by Taiwanese media and became a hot topic in Japan as well. Of course, you can't measure the popularity of Taiwan as a whole just by looking at one bus, but this is an example of an online story being recognized to the extent that it has been brought into the real world.

Why is it compatible with Chinese-speaking countries?

We will think about its spread in the Chinese-speaking world by focusing on how to create numerical vocabulary and videos.

• The closeness of the video culture of Niconico → Bilibili:The ways of enjoying the videos are similar, such as barrage comments, MAD, and Kiku (on MAD type).
• You can use it even if you don't fully understand the words: Just faces, numbers, voices, and movements can be a good joke.
• Strong number meme: 114514 and 810 can be copied without understanding Japanese.
• Translation itself becomes a derivative work: New material is created by paraphrasing Japanese idioms and sayings into Chinese.
• Easy to re-edit:Even users who do not know the original video can participate from the already processed template.

Are Inmu and LGBT/homosexual culture the same thing?

It's not the same. The original work is an adult-oriented video between men, but the online ``inmu'' is a meme culture that uses that video as material. It does not represent LGBT culture or the gay community itself.

Also, due to its origins and the nature of its expression, there are some parts that could be interpreted as treating homosexuality as a laughing matter. Posting a large number of words in public places or in unrelated posts may not only result in "inside jokes not getting through," but may also lead to discomfort and nuisance.

Consider real people and internet memes separately.

Inmu culture has reused performers' footage for years. But a meme character and the real person who appeared in the footage are different. Searching for someone's current address, occupation or real name, or contacting strangers assumed to be that person, is outside this site's purpose.

The setting on the meme "Yajū Senpai" should not be treated as the background of the performer himself.

Relationship with INMU KING

INMU KING is a work that reconstructs the promise of the characters, words, and images of Inmu that have been accumulated in this way into a generative AI/pop MV-like expression for 2026.

What's interesting is that it's not just aimed at people who know old footage. There are multiple ways to enter, such as listening to it as a song, viewing it as an AI video, investigating the source material, and creating derivative AI collages. As a result, the memes formed in the 2000s-2010s are once again connected to the production environment of 2026.

Frequently asked questions

Q. Do “Inmu” and “Yajū Senpai” mean the same thing?

No. "Inmu" is a broad term that refers to the original work and the entire derived culture, and "Yajuu Senpai" is a representative figure/meme within it.

Q. Is Koji Tadokoro his real name?

This site does not treat information that has been confirmed as your real name. It has become very widely established as a setting and name on the Internet.

Q. What is 114514?

This is one of the most famous number memes related to Yajū Senpai. It has become established as a rhyme and audible expression that connects the sounds in the story to numbers, and is used as it is not only in Japan but also in Chinese-speaking countries.

Q. What is 810?

This number is used as a pun to replace "beast" with a number. This is also the reason why August 10th is treated like "Beast Day" on the internet.

Q. Is it still popular?

The overwhelming amount of posts on Nico Nico Douga in the early 2010s and the spread on SNS, overseas, and generative AI in the 2020s are different in nature, so a simple numerical comparison is not possible. However, in 2026, we can still see INMU KING's hit, new explanatory videos on China's Bilibili, and meme examples in Taiwan, and the culture itself continues to change in form.

Summary

What is unusual about Inmu is that a work from 2001 was not just preserved as an "old internet joke." Lines have become vocabulary, people have become characters, videos have become materials, and even the way we write comments and create videos has become a part of our culture.

So it can be reused as new platforms and production techniques emerge. From Niconico Douga's audio MAD to Bilibili's brutal video to the generative AI work of 2026, the structure of ``rearranging and playing'' has remained almost unchanged even though the medium has changed.

This is thought to be one of the reasons why inmu has remained on the internet for over 20 years and has even crossed national borders.

Main reference materials

• Mochimochi "YAJU＆U" — YouTube
• Oricon weekly TikTok music chart dated May 8, 2025 — YAJU&U;'s chart posted
• ASCII.jp "The world of Inmu that are very Niconico-like in a sense" 1/3 — Work origin, number of posts, Niconico Douga statistics from 2007 to 2014
• ASCII.jp "In a sense, the world of Inmu videos that are very Niconico-like" 2/3 — Center shift to Yajū Senpai, BB Senpai Theater, live dream commentary, comment culture
• Know Your Meme "A Midsummer Night's Lewd Dream" — Explanation/derivative items in English speaking countries
• Weekly Women's PRIME "Who is the Japanese 'Yajū Senpai' who is the big bus in China?" — Spread to China and Taiwan
• Bilibili "Wild first?" — An example of an explanatory video in a Chinese-speaking country
• Bilibili "Wild Master: 114514 to 114514 to 1 1 1 2!" — An example of a new commentary video as of 2026
• Bilibili: “What are Yajū Senpai and 114514?” — terminology in Chinese-speaking communities
• TOY-PEOPLE "Japanese user takes photo of 'Yajū Senpai Meme Bus' in Taiwan" — Case study in 2026 in Taiwan

Because internet memes are prone to information confusion and jokes becoming factual, this article separates publicly available information that can be confirmed from online common names and interpretations as much as possible. Please let us know if there are any errors or primary materials that should be added to contact@inmuking.jp.