第一ホテル殺人事件 - Wikipedia

『【増補改訂】新橋第一ホテル女性歯科医殺人事件 1972年』
新橋第一ホテル女性歯科医殺人事件1972年週刊現代 1972年7月13日号 【事件の概要】 毎日新聞(1972年6月26日夕刊) 1972(昭和47)年6月2…
On June 26, 1972, Ayako Tanizaki (then aged 37), a dentist from Yatsushiro City , Kumamoto Prefecture, was found murdered, naked and face up on the carpet in Room 3304 on the third floor of the new wing of the Shinbashi Daiichi Hotel (now the Daiichi Hotel Tokyo) in Tokyo.
The body was covered with the hotel's yukata, his girlfriend's dress, and underwear.
A post-mortem autopsy revealed that the cause of death was asphyxiation caused by being strangled with a hand or a wide belt-like object. Based on the contents of the stomach, the estimated time of death was one to two hours after eating, around 8:00 p.m. There were no signs of the bed or shower having been used, so it was believed that Taniwaki had been killed immediately after returning to his room.
There was subcutaneous bleeding all over her body, likely due to her desperate resistance after being attacked, and guests in the next room heard the woman's screams of "Help! Someone come!" but hesitated to call the front desk or the police.
The body was found to have been sexually assaulted after death.

Ayako Tanizaki
The body was discovered by two male acquaintances of the victim, a dentist (Mr. A and Mr. B), who had come to Tokyo from Kumamoto with the victim, and a hotel employee.
Tanizaki, Mr. A, and Mr. B had come to Tokyo on the 24th to participate in a two-day training course held by the Japan Dental Association on the 12th floor of Kasumigaseki Building starting on June 25th.
After the training session on June 25th, the three men had dinner together at a yakitori restaurant under the train tracks in Yurakucho from around 6:30 pm, but Tanizaki said he was feeling unwell and returned to the hotel by himself around 7:30 pm.

Dining area under the Yurakucho railway tracks
Afterwards, one of the two men who had gone to see the movie, Mr. A, reportedly said he was feeling unwell and returned to the hotel at around 8:30 pm, where he lay down in his own room, which was diagonally across from Tanizaki's room.

Yomiuri Shimbun
When Mr. B returned from the movies around 11:00 p.m., the two of them knocked on Mr. Taniwaki's room to settle the bill from the yakitori restaurant, but there was no answer.
At around 9:00 a.m. on the following day, June 26th, the two men became suspicious when Tanizaki took so long to wake up that they knocked on her door, but there was still no response.
So they asked a hotel employee to open the door for them and when they went inside, they found Tanizaki lying on the floor, completely changed.