A Guilty Plea in Courtroom Terms
A former professor at the University of Tokyo's Graduate School of Medicine pleaded guilty on September 25 to accepting bribes. The bribes came as nights out: prosecutors say a research partner paid for the professor's visits to soaplands and high-end hostess clubs in Tokyo.
Sato Shinichi, 63, a dermatologist, admitted the charge at his first hearing at the Tokyo District Court. "I have damaged the public's trust in public service, and I am sorry," he told the court, according to the Sankei Shimbun.
Prosecutors asked for two years in prison and forfeiture of about 1.83 million yen, roughly the value of the entertainment. The hearing concluded the same day. The court will hand down its verdict on October 22.
The Charge
According to the indictment, as reported by Kyodo News and the Sankei, the offense ran from March 2023 to August 2024. During that period Sato allegedly helped the former representative director of a general incorporated association, the Japan Cosmetic Association. The favors involved setting up and running a shakai renkei kōza, an industry-funded research chair at the university. The chair studied whether cannabis-derived compounds could treat skin disease.
In return, prosecutors say, Sato received entertainment on 28 occasions, worth a combined 1.83 million yen or so, at soaplands and high-end clubs in Tokyo.
The University of Tokyo is a national university corporation. Under Japanese law its faculty are treated as public officials for bribery purposes, so a professor's favors to a private partner can be prosecuted the same way as a civil servant's.
In closing arguments, prosecutors said the entertainment went on for a year and five months. They said the professor asked for it himself, under the label of "meetings," and that it included trips to soaplands. That conduct, they argued, deserved strong condemnation. The defense asked for a suspended sentence. It argued that Sato had already been punished by society, including his disciplinary dismissal from the university.
What a Soapland Is
A sōpurando is a licensed bathhouse. Japan's fūei-hō (the Businesses Affecting Public Morals Regulation Act) classifies it as a storefront sex-related business. It must file with the prefectural public safety commission and operate only in zoned districts. In Tokyo, the best-known cluster is Yoshiwara in Taitō Ward, the area Tokyo Reporter identified when Sato was arrested. Its prices are among the highest in the domestic sex trade.
Soaplands have been under legal pressure in 2026. The baishun bōshi-hō (the Anti-Prostitution Act) makes it a crime to provide premises for prostitution as a business. Police have used that provision this year to raid soaplands in several prefectures, including Gifu's Kanazuen district and Matsuyama's Dōgo area. This case does not turn on anything that happened inside the venues. Sato is charged only with accepting their cost as a bribe.
How the Case Unfolded
Tokyo Metropolitan Police arrested Sato in January 2026. At the time, he had been a professor of dermatology at the university since 2009. According to Tokyo Reporter's account of the arrest, the research chair opened in April 2023. It was halted in March 2025 after the relationship with the association broke down around August 2024. In May 2025, the association's representative director sued, seeking 42 million yen in damages and arguing that the chair's termination was invalid.
The other two defendants have already been sentenced:
| Defendant | Charge | Outcome |
|---|---|---|
| Former representative director, Japan Cosmetic Association (53) | Bribery | Convicted; judgment final |
| Former project associate professor under Sato (47) | Bribery (receiving) | One year in prison, suspended for two years, plus forfeiture of about 1.96 million yen; judgment final |
| Sato Shinichi, former professor (63) | Bribery (receiving) | Pleaded guilty Sept. 25; prosecutors seek two years; verdict Oct. 22 |
The associate professor was sentenced in May 2026. The forfeiture ordered in that case was larger than the amount prosecutors now attribute to his former supervisor. NHK reported at the time that the court found the younger researcher had also actively wanted the entertainment.
Why It Matters
The case has been covered in Japan as an academic scandal: the country's top university and a cash-for-access arrangement in a field, cannabinoid medicine, that is still politically sensitive. Its connection to the sex trade is narrower but concrete. Japan's corporate settai (hospitality spending on a person whose favor is being sought) has long been handled through the nightlife economy. Hostess clubs and, less often, sex-industry venues sit at the expensive end of that system.
For a public official, the price of the evening is not the only legal issue. The evening itself counts as the bribe. Prosecutors have now brought that theory to verdict twice in one case, and they are asking for a prison term on the third.
Sources: Kyodo News, September 25, 2026 (via Chunichi Shimbun and Yahoo! News Japan), for the guilty plea, the defendant's name and age, the March 2023–August 2024 period, the research chair on cannabis-derived compounds for skin disease, the 28 occasions and about 1.83 million yen in entertainment at Tokyo soaplands and high-end clubs, the sentencing request, the October 22 verdict date, and the final judgments against the briber and the former project associate professor (one year suspended for two years, about 1.96 million yen forfeiture). Sankei Shimbun, September 25, 2026 (via Yahoo! News Japan), for the defendant's statement in court, the prosecution's closing argument on the one-year-and-five-month duration, entertainment requested under the name of meetings and including soaplands, and the defense's request for a suspended sentence citing his disciplinary dismissal. Same-day reports by NHK, the Asahi Shimbun, the Yomiuri Shimbun, Jiji Press and TV Asahi confirm the guilty plea and the two-year request. NHK, May 22, 2026, for the associate professor's sentencing. Tokyo Reporter, January 25, 2026, for the arrest, the Taitō Ward soapland location, the defendant's career, and the timeline of the research chair and the civil suit. Glossary: fūei-hō = Businesses Affecting Public Morals Regulation Act; baishun bōshi-hō = Anti-Prostitution Act; sōpurando (soapland) = a licensed bathhouse-type sex business; settai = hospitality or entertainment provided to a client; shakai renkei kōza = an industry-funded collaborative research chair. Sato has pleaded guilty but has not been sentenced. The other two defendants are identified only by role, as in the Japanese wire reports, and no allegation is made here against any soapland or club operator.