Reiwa 6 (Wa) No. 53 Injury, Instigation of Abandonment of a Corpse, Anti-Prostitution Law Violation Case

In March 2025, Tokyo police discovered the body of Ayaka Sato, a 23-year-old woman working in the sex industry, dumped in a forested area in Yamanashi Prefecture. The investigation revealed that Kenji Tanaka, a 45-year-old club manager, had violently assaulted Sato in his apartment following a financial dispute linked to her earnings, causing fatal injuries. Panicking, Tanaka called his acquaintance Daichi Suzuki and instructed him to dispose of the body. Tanaka was also found to have been managing Sato’s prostitution activities, taking a large cut of her income in violation of the Anti-Prostitution Law. The case was registered under Reiwa 6 (Wa) No. 53, combining charges of injury causing death, instigation of corpse abandonment, and prostitution law violations. The trial focused on whether the fatal blow constituted intent to kill or injury, and on Tanaka's role as a predatory exploiter.

The Tokyo District Court found Kenji Tanaka guilty of injury causing death, instigation of abandonment of a corpse, and violation of the Anti-Prostitution Law. He was sentenced to 10 years in prison. Daichi Suzuki received a 2-year suspended sentence for abandonment of a corpse.

The primary disputes centered on whether Tanaka's assault constituted injury causing death or the more serious crime of homicide; whether his command to Suzuki met the legal threshold for instigation of corpse abandonment, given Suzuki's full awareness; and the extent to which the Anti-Prostitution Law applied to the "management" of a single sex worker in an unlicensed business.

The case intensified public scrutiny of Japan's underground sex industry, highlighting extreme labor exploitation and violence against vulnerable women. It sparked online campaigns demanding stricter enforcement of the Anti-Prostitution Law and better protection for sex workers, while reigniting debate on the legal gray zones that enable such abuses.