<figure id="attachment_442685" class="wp-caption alignnone" style="width: 810px;" aria-describedby="caption-attachment-442685"><a href="#" data-ident_hash="330ca4e2"><img src="https://res.cloudinary.com/fridaydigital/image/private/t_article_image/wpmedia/2025/10/c18643d4adb43e612539ad166c7e3d32.jpg" alt=""></a><figcaption id="caption-attachment-442685" class="wp-caption-text">Defendant Kosemura, nicknamed “Kosemu,” was popular among students. But his hidden side was that of a horrifying criminal.</figcaption></figure>
<h2>Defendant Kosemura, who admits to the contents of the indictment</h2>
“There is no mistake. I am truly sorry.”
October 2, 10 a.m. — Wearing a white polo shirt, black pants, and a white mask, 37-year-old defendant Fumiya Kosemura, in handcuffs, entered the courtroom. The high public interest was evident, with more than 100 people applying for the 21 seats in the gallery.
Kosemura’s bangs had grown long, with strands of gray hair visible. Throughout his testimony, he kept his head down and his hands clasped in front of him.
That day’s trial lasted only 15 minutes — but in those 15 minutes, the mask of the man once affectionately called “Kosemuu” by his students completely fell away.
According to the indictment, between January and February of this year, at a facility in Kanagawa Prefecture, Kosemura used a tablet device to secretly record videos of a young girl’s underwear and shared the footage in a group chat on social media.
He had also engaged in similar acts of voyeurism in June and July of last year. In addition, he allegedly filmed videos exposing the genital area of a young girl, inserted his fingers inside her underwear, and touched her genitals.
Furthermore, in October last year, at another facility in Kanagawa, he reportedly pressed his genitals against the buttocks of a different girl. In April of the same year, he allegedly recorded six eight-year-old girls changing their clothes and saved the videos.
Kosemura admitted to the charges in the indictment. A reporter from a national newspaper’s social affairs department stated:
“Among the members of the group, Kosemura is considered the most malicious.”
Indeed, on October 6, the investigative headquarters of Atsuta Police Station in Aichi Prefecture re-arrested Kosemura on suspicion of property damage and non-consensual indecent acts. This was for allegedly applying bodily fluids to recorders and other instruments belonging to three young girls at a facility in Kanagawa between last year and this year.
Kosemura admitted to the allegations, stating:
“Other members of the (chat) group had posted videos of themselves putting bodily fluids on instruments, and after seeing that, I wanted to do the same.”
Police investigations so far have revealed that the chat group Kosemura belonged to was created by Yuji Moriyama, a 42-year-old head teacher at a Nagoya municipal elementary school, who had been arrested around the same time and indicted for violating the same law.
At that day’s first trial session, the meeting between group leader Moriyama and Kosemura was brought to light.
<div data-friday-nextpage-lead="The investigation expanded from Aichi Prefecture to a nationwide investigation."></div>
<h2>Invited teachers who shared the same sexual preferences</h2>
In the opening statement, it was explained how the chat group came to be. Defendant Yuji Moriyama allegedly began secretly filming girls in their underwear about ten years ago. Later, he started communicating via a messaging app with people on social media who also claimed to be teachers sharing the same sexual preferences. Among them was defendant Fumiya Kosemura.
A reporter from the national paper’s social affairs department explained:
“Moriyama was concerned about the number of participants and the risk of information leaking. For that reason, around August of last year, he began using a highly anonymous app and invited only a few members he considered trustworthy. Kosemura was recognized by Moriyama as trustworthy and joined the new group.”
This group had around 8 to 10 participants, all of whom voluntarily recorded voyeuristic videos and uploaded them themselves. However, in March of this year, the group’s existence came to light after Shota Suito, a 34-year-old former teacher at a Nagoya municipal elementary school, was arrested for property damage for applying bodily fluids to the backpack of a 15-year-old girl.
A representative from a Nagoya-based TV station revealed the background:
“Initially, this case was supposed to be handled only by the Aichi Prefectural Police, but due to the extreme maliciousness of the crimes, arrests continued one after another. As more teachers were arrested, the Minister of Education even commented on the matter, turning it into a national-level issue. The National Police Agency contacted the Aichi Prefectural Police, putting pressure on them to ‘arrest every single person involved.’ On July 22, a large-scale investigation headquarters led by the Director of the Community Safety Department was set up at the Atsuta Police Station, with a team of 74 officers.”
However, the chat app Moriyama had chosen was so anonymous that it was said to have been used by the German military and the U.S. Department of Defense.
“Because of that, analyzing the chat took a long time, so investigators resorted to manually searching for coded terms on social media, using manpower to track and arrest members one after another. In early September—about a month and a half after the first arrests in late June—they arrested a junior high school teacher from Hayama, Kanagawa Prefecture. By mid-September, they had also arrested a junior high school teacher from Hokkaido. About 3 to 5 suspects remain at large, and the Aichi Prefectural Police are still desperately searching for the remaining teachers,” the TV station representative said.
The first public trial of group leader Moriyama is scheduled for the end of this month. The vile acts committed by these teachers must never be allowed to go unpunished.

 Kyodo

 The "Teachers' Group Child Voyeurism Case" terrorized not only children but also their parents. The shocking "backstage face" of Fumiya Kosemura, one of the core members of the group, was revealed at his first trial. ......

Horrifying Details Emerge at Trial of Kosemu Teacher Accused of Child Voyeurism

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