Prosecuted Tokyo University Professor’s Begging Behavior Traced to Bangkok Trip, Exclusive Photos Obtained
Former professor of the Graduate School of Tokyo University was arrested and indicted on bribery charges after he was forced to "entertain at Yoshiwara soap operas", indulged in lavish entertainment with his research collaborators, and went on a bribery spree.
“I never imagined I could hold such a beautiful woman”
〈The reason I thanked excessively in Thailand was because I was happy that the girls flinched at the boss’s assertiveness.〉
From the LINE chat history, one can almost picture the boss’s delight——.
Shinichi Sato, a former professor at the Graduate School of Medicine, University of Tokyo (62), was arrested by the Tokyo Metropolitan Police on January 24 on suspicion of accepting bribes and was indicted on February 13. He is suspected of receiving nearly 5 million yen in entertainment, including visits to sex-related establishments, from the Japan Cosmetics Association in exchange for favors in joint research on the effects of cannabis components. Ayumu Yoshizaki, a former specially appointed associate professor (46) who was Sato’s subordinate, was also sent documents for the same suspicion.
How did the famous professor, who had served as head of dermatology at the University of Tokyo Hospital, transform into a sex-entertainment monster? The author obtained photos from Sato’s first experience receiving sexual entertainment during a 2-night, 3-day Bangkok business trip.
The opening message shows “Boss Sato” expressing gratitude to Koichi Hikichi (52), the representative director of the association (sent documents for bribery), via Yoshizaki after returning from the Bangkok trip. The trip was conducted in early March 2024 as part of the research, with Sato and Yoshizaki visiting a cannabis field and other sites, guided by the association’s research partners.
The first night was as follows. After finishing dinner, the group entered a top-class club in central Bangkok. They were shown to a huge VIP room equipped with a billiard table and a bar counter. Hikichi recalls that time:
“Models lined up, and you could designate one to drink with you. Sato and Yoshizaki were happily chatting in English. We stayed in the club for about three hours, I think.”
The club had a system where women could be taken to the hotel. Sato and Yoshizaki had received entertainment at clubs in Ginza before, but for prostitution, there might have been objections due to their positions. Being considerate, Hikichi gently asked Sato, “It seems you can take them with you, how about it?” Sato immediately replied, “Absolutely!!”
“He said it with incredible enthusiasm, as if spitting was flying. Sato negotiated with a model resembling Nanao, and Yoshizaki with a woman resembling Miwako Kakei, and got consent. Then suddenly, they started fidgeting as if they wanted to go home quickly.”
Hikichi, who stayed in a hotel room next to Sato’s, recounted that while working at midnight, he could hear the women’s seductive voices through the wall.
The next morning, Sato approached Hikichi with a beaming smile to express his gratitude:
“I never thought I could hold such a beautiful woman. It was a fun night.”
On the second day of the trip, a female doctor from Japan participated, so the nighttime debauchery was skipped.
“Since February 2023, Sato and the others had forced me to entertain them at high-end restaurants and clubs in Ginza. Considering Sato’s authority, I thought our joint research would be ruined, so I had no choice but to comply with the unreasonable demands. I knew he liked women from the way he behaved in Ginza, but I never imagined it would go this far.” (Hikichi)
Whatever he does, sex entertainment comes first
Sato’s libido, ignited in a single night, became unsatisfied with Ginza clubs that involved no physical contact with the skin, his own field of expertise. During the first entertainment session after returning to Japan, he reportedly said:
“The clubs are too expensive, and you can’t even hold hands or kiss.”
Since then, the location for secondary entertainment was changed from Ginza to a high-end soapland in Yoshiwara, costing 80,000 yen for 120 minutes. Sato’s demands escalated further. Hikichi recalled with exasperation:
“Sato told me, ‘If we go to sex entertainment after the dinner, I don’t get fully aroused, so reverse the schedule.’ From then on, we went to Yoshiwara first and had dinner afterward. After his wife discovered the HIV-prevention supplements he was taking, he requested, ‘Move the Yoshiwara time earlier, around noon, so it doesn’t look suspicious.’”
The extreme demand came when Sato asked to use the shower room of a company affiliated with the association before going to the sex establishment. Sato, it seems, had a strange pride in wanting to show cleanliness to the regular hostesses. Employees were barred during that time, forcing a halt in operations.
Hikichi’s patience finally snapped at the end of summer 2024, after being intimidated by Sato at a dinner meeting. He filed a complaint with the police and, in May 2025, filed a lawsuit seeking about 42 million yen in damages from Sato and others. The obtained complaint states incidents such as:
〈“I could shut down your lab (joint research) tomorrow,” “I will socially annihilate you,” and “If you don’t want your lab destroyed, bring me 15 million yen.”〉
Hikichi expressed his anger clearly:
“Here’s a man who didn’t even pay himself, using his authority to make endless demands. On top of that, the research was destroyed, debts increased—our survival was at stake. Just remembering it makes me furious.”
Is there any excuse for the disgrace of a charismatic professor who drowned in authority and lust? (Some honorifics omitted)
From the February 20/27, 2026 issue of “FRIDAY”
Reporting and writing： Takehide Mizutani (nonfiction writer)