Forum folklore
Japan · 2001
- Status
- Meta-legend
- Reading time
- 7 minutes
- Origin
- A 2channel thread, May 2001
- Confidence
- Thread date cited; the incident itself is fictional
Nobody can say it
The Samejima Incident
Somewhere in the history of the Japanese internet, the story goes, there was an incident so dreadful that anyone who learns the details is silenced. Everyone has heard the name. Nobody can say what happened, because nothing did.
By the Yokai Signal editors · Published
Every legend leaves two records: the story people repeat, and the path it took to reach them.
01 / THE STORY
An incident with a name and no content
As retold, the Samejima Incident is the darkest episode of the early Japanese internet, an affair on the anonymous board 2channel so grim that those who find out what it was are said to be “erased” (kesareru, 消される). Because anyone who learns the truth disappears, nobody is able to explain it. The eerie result is that the only thing left in circulation is the name.
Notice what the legend does not contain: a victim, a place, a date of the supposed crime or a culprit. A reader who asks for details is told, in effect, that asking is the dangerous part. Some retellings add rumors of many victims or of an official cover-up, but these are decorations on an empty frame, and different tellers decorate it differently.
That makes it a close cousin of Ushi no Kubi, the older tale of a ghost story too frightening to repeat. Both are legends whose content has been removed, leaving only a reputation. The Samejima Incident is the version built for a message board.
Everyone knows the name. No one is allowed to say what it means.
02 / THE TRACE
A thread in May 2001
The paper trail is short. A Shobunsha essay by the occult writer Yoshida Yūki cites a 2channel thread titled 伝説の「鮫島スレ」について語ろう, roughly “Let’s talk about the legendary ‘Samejima thread’”, dated May 24, 2001, as the starting point of a series of related threads. A 2024 column in BCN Retail agrees that the matter began on 2channel in 2001 with a thread of that name.
The title is itself the trick. It speaks of a legendary thread that, as far as anyone can tell, had no history yet. According to the BCN column, the person who opened the thread wrote that many readers might not know about it but long-time 2channel users would remember it. That flattering line invited visitors to pretend they remembered, and the pretending became the legend.
MOVIE WALKER PRESS, writing in 2011, says the story had by then circulated on the board for about ten years and states plainly that it began with a netizen’s thread, a joke built on the “don’t talk about it” convention.
We could not open an archived copy of the original thread, so we cannot say what its first replies contained. Everything about its wording comes from the secondary sources named here. One footnote in the Shobunsha essay appears to be mis-numbered, so we treat the May 24, 2001 date as cited, not independently confirmed.
03 / HOW THE GAME WORKS
Playing along is the whole mechanism
The Samejima thread is best understood as a collaborative performance with unwritten rules. Rule one: act as if the incident is real. Rule two: never state what it was. Rule three: react with alarm whenever someone gets too close, with stock lines of the kind INTERNET Watch noticed in 2011, such as warning that a person will be “erased” or begging a poster to stop reminding everybody.
Because every participant is both audience and performer, the legend needs no author. A newcomer who asks what happened is answered with nervous silence, which is precisely what an outsider reading the thread would expect if something awful lay beneath. A newcomer who plays along adds one more voice to the chorus. In that sense the legend manufactures its own evidence.
A Japanese film listing for the 2011 movie describes the arc in the same terms: first a joke or urban legend, then, as rumors multiplied, a stream of supposedly detailed accounts that made the fear feel real, with the ban on investigating only sharpening curiosity. We cite that as the film’s framing, not as an account of the thread.
04 / THE WORDS
Samejima, kesareru and the taboo
Samejima (鮫島) is a surname, and in the legend it is simply the label attached to the event. The kanji can be read literally as “shark island”, but the legend does not use that image, and we found no source claiming the surname was chosen for a particular meaning. We treat the name as arbitrary.
Jiken (事件) means an incident or a case, the same word used for crimes and accidents. Putting it on a story with no events gives the name the weight of a news headline. Kesareru (消される) is the key verb: to be erased, wiped out. It is deliberately vague about whether the victim is deleted from the internet, from society or from life.
Yoshida Yūki uses the Samejima thread in a discussion of kataranu taboo, a custom of marking something as unspeakable and then telling it quietly all the same. He calls the 2channel case far lighter in tone than the human-sacrifice legends he is examining, but cites it as proof that the pattern still happens today.
05 / CONTEXT
Why an anonymous board could make a taboo
Interpretation: 2channel’s anonymity and speed made it ideal for a legend of this shape. Without usernames, nobody could be wrong about who started it, and a claim that “veterans remember” could neither be proven nor refuted. The wording matters: appeals to insider memory are an old social lever, and on a board whose culture prized being in the know, they were hard to resist.
A taboo is also a very efficient piece of folklore. Ordinary ghost stories need a plot to be retold; a ban on speaking needs nothing but the ban. The legend travelled well because it could be reduced to a name, and a name fits in a single post, a sticker or a film title. MOVIE WALKER PRESS and INTERNET Watch both note that the content has never been revealed and that the taboo is what has been handed down.
The game carries a risk of its own, which journalists noticed. Reporting on the 2011 film, MOVIE WALKER PRESS recorded that some commenters felt the production should consider the families of the victims, even though there were no victims. A fictional taboo can produce real discomfort, which shows how convincing the performance became.
06 / ON SCREEN
Two films, nine years apart
The incident reached cinema twice. INTERNET Watch’s column of June 28, 2011 reported that a film would be made; the picture, 2ちゃんねるの呪い 劇場版 (Curse of 2channel: The Movie), opened on August 6, 2011 according to MOVIE WALKER PRESS. A programme listing credits Nagae Jirō as director. According to INTERNET Watch, the official story does not depict the incident itself but the human drama around it.
The reception was mostly in character. INTERNET Watch quotes 2channel users who first took the news for a prank and answered with the standard jokes, such as that the director would be erased. The audience was playing the same game around the film that it had played around the thread.
In 2020 came 真・鮫島事件 (Shin Samejima Jiken, “The True Samejima Incident”), released nationwide on November 27, 2020, starring Takeda Rena. Eiga.com lists the director as Nagae Jirō and the running time as 80 minutes, calling the legend the film’s source idea. MOVIE WALKER PRESS says it updates the legend for the Reiwa era, with rumors spreading through remote gatherings and social media.
07 / WHY IT WORKS
A ghost story made of manners
Interpretation: the Samejima Incident works because it asks very little. There is no text to memorize, no villain to believe in, just a convention that everyone agrees to honor. The fear it produces is closer to social awkwardness than terror, the feeling of walking into a room where people stop talking.
That is also why it is more a comment on online communities than a ghost story. It shows how a group can generate a shared secret on demand and how quickly an empty space attracts rumor. Ushi no Kubi achieved the same effect with writers and newspapers in the 1960s; the Samejima thread reached it in a single afternoon of posting.
For readers outside Japan the safest summary is the plainest one. There is nothing to find, and the absence is the point.
08 / TIMELINE
The record, in order
- May 24, 2001
The 2channel thread 伝説の「鮫島スレ」について語ろう is cited by Yoshida Yūki as the start of a series of related threads.
- 2001
BCN Retail dates the beginning of the legend to a thread opened on 2channel this year.
- June 28, 2011
INTERNET Watch’s Yajiuma Watch column reports that a film based on the incident is planned.
- August 6, 2011
The film 2ちゃんねるの呪い 劇場版 opens, according to MOVIE WALKER PRESS.
- November 27, 2020
The film 真・鮫島事件, starring Takeda Rena, opens nationwide.
- March 15, 2024
BCN Retail publishes a column calling it a fictional incident and comparing it with Ushi no Kubi.
09 / QUESTIONS
Common questions
What is the Samejima Incident?
The Samejima Incident (鮫島事件) is a Japanese internet legend about an incident so terrible that those who learn the details are said to be “erased”, so nobody can explain it. Journalists describe it as fictional. It grew out of a 2001 thread on the anonymous board 2channel and survives mostly as a name and a taboo.
Did the Samejima Incident really happen?
No evidence suggests so. BCN Retail calls it a fictional incident, and MOVIE WALKER PRESS says it began with one netizen’s thread, a joke based on the “don’t talk about it” convention. No victim, place or date of any actual event has ever been attached to it.
Why does nobody explain the Samejima Incident?
Because the legend’s central rule is that anyone who learns the details is silenced, which conveniently means no explanation can exist. In practice there is nothing to explain. The silence is the part that was invented, and 2channel users kept it going by reacting with mock alarm whenever someone asked.
Is the Samejima Incident connected to Ushi no Kubi?
Only in structure. Both are legends about content nobody will repeat. Yoshida Yūki’s Shobunsha essay places the Samejima thread beside Ushi no Kubi as an example of an unspeakable topic, and BCN Retail compares the two. They are not related by origin: one is a 1960s writers’ joke, the other a 2001 forum thread.
Have there been movies about the Samejima Incident?
Yes, two. 2ちゃんねるの呪い 劇場版 opened on August 6, 2011, and 真・鮫島事件 opened on November 27, 2020 with Takeda Rena in the lead. Both invent their own plots around the legend, since the legend itself has no story to adapt.
10 / SOURCES
Follow the signal
Sources are listed by what they help establish. A source documenting a legend’s circulation is not proof that the supernatural event occurred.
11 / RELATED
Continue the trail
Browse the full archive or see every legend on the timeline.