The Shimoyama Incident: Conflicting Autopsies and the Body-Double Theory

At about 9:37 a.m. on July 5, 1949, Sadanori Shimoyama, the first president of Japanese National Railways, entered the Mitsukoshi department store in Nihonbashi and never returned to his waiting official car. Early the next morning, his body was found on railway tracks in Ayase, Adachi Ward. The video asks why the missing hours and conflicting examinations produced a controversy that has lasted so long.

Reported sightings of Shimoyama—or of someone who closely resembled him—after his disappearance extended from inside Mitsukoshi to the Ginza subway line and the area around Gotanno Station. There were also accounts of a stay at an inn and sightings along the railway, but none established that the person was Shimoyama. The timeline leads to a freight train passing at about 12:20 a.m. and severing the body.

The forensic pathologist who conducted the autopsy is said to have found no vital reaction in the injuries and suggested the possibility of murder, with the body placed on the tracks after death. A medical examiner who inspected the scene countered that internal bleeding also appears in people killed by trains and that the small amount of blood could have been washed away by rain, rejecting it as evidence of murder. The opinions split over whether he was struck before or after death, and in August 1949 the disagreement led to a forensic pathologist being called before the Diet.

Behind the case were early Cold War anticommunist policy and austerity under the Dodge Line, which put JNR under pressure to make mass staff reductions. The Japanese Communist Party had gained seats in an election, while the communist-aligned railway union took an increasingly confrontational stance toward the cuts. The video presents the incident's occurrence one day after JNR notified about 30,700 people of dismissal as part of the context that encouraged murder theories.

The Mainichi Shimbun, meanwhile, reported a suicide theory based on witness statements and forensic opinions. Records that Shimoyama had been diagnosed with a neurasthenic depressive state and was taking sleeping medication are also presented as support for that view, although no diagnosis should be asserted retrospectively from this account. The special investigative headquarters was eventually dissolved without announcing an official conclusion of either murder or suicide, and the investigation was reportedly scaled back.

A man who became JNR's second president later wrote in a magazine that the person seen at the inn was a double and that Shimoyama had been killed. Seicho Matsumoto also developed a body-double and murder theory in *Japan's Black Fog*, citing details including the absence of cigarette ends in the inn's ashtray. A book by an Asahi Shimbun reporter is said to have reached testimony suggesting involvement by a U.S. military-linked intelligence organization, but all of these remain unconfirmed theories introduced by the video. The three people involved in a 1999 *Weekly Asahi* series are also said to have later leaned toward murder, while the ending leaves the truth unresolved.