The Beginning of Unit 731 and Ishii Shiro's Career

by Evan Thompson

​In 1932, Surgeon General Shiro Ishii was in charge of the Army Epidemic Prevention Research Laboratory (AEPRL). Ishii, who had had a lengthy military career up to this point, had a prominent background in medicine. After earning his medical degree from Kyoto Imperial University in 1920, Ishii joined the Imperial Army under the rank of Surgeon Lieutenant. Ishii quickly proved to be a skilled social climber as he quickly rose through the army ranks. 

In 1926, Ishii completed a doctorate in microbiology from Kyoto Imperial University. During his attendance at Kyoto Imperial University, Ishii had involved himself with various secret societies, many of which exerted a strong influence over the Japanese military. In addition to participating in secret societies, Ishii became interested in biological weapons, believing them to be effective weapons for future warfare. 
After Ishii was appointed to the commander of the Army Epidemic Prevention Research Laboratory, with the backing of Colonel Chikahiko Koizumi (who also helped Ishii become a professor of immunology at Tokyo Army Medical College), he established a top-secret biological weapons research group called Unit Tōgō. 
Unit Tōgō was located in the Japanese puppet state of Manchukuo, about 100km away from Harbin, in Beiyinhe. It was meant for chemical weapons experimentation, biological weapons experimentation, human experimentation, and the production of deadly weapons. The army forced peasants to sell their ancestral land to be used to construct a massive facility. Ishii and his 300 laboratory staff conducted various experiments on the prisoners held in the facility. Experiments included horrific practices such as routinely taking large amounts of blood from prisoners, using electric currents to electrocute prisoners, hitting prisoners over the head with an ax, and immediately harvesting their organs for study. If these prisoners survived the experiments, they would eventually be "sacrificed," as the facility researchers saw no further use for them.
However, even before Unit Tōgō, Ishii had begun human experimentation with biological weapons during his tenure as a professor at the Tokyo Army Medical College. Ishii used his position as a professor in the Department of Immunology to hide his actions from his university colleagues, the general public, and foreign forces. As early as 1930, Ishii began his research on biological weapons before moving to Manchuria to continue his experiments since it was hard to conceal his activities in Tokyo. ​

Photo of a building within Pingfang

Aerial view of Pingfang

The Pingfan Facility
In 1936, after Unit Tōgō was compromised due to a prison break. After the prison break, the locals had realized the plans. After this incident, Ishii Shiro realized that he needed more funds to secure his research complex and expand his research interests. The amount of money he needed was something that someone in high power could have only approved. According to a document, Emperor Hirohito approved an expansion of Shiro Ishii's fund for his research. However, it is unclear whether or not the Emperor knew the true purpose of this new research complex. It was to be known as the Anti-Epidemic Water Supply and Purification Bureau, otherwise known as Unit 731. The main facility was constructed in the Pingfang district of Harbin. As head of the Bureau, Ishii had free reign to assign, plan, and build new "water purification factories" wherever he wished. These new "factories" did actually conduct legitimate water purification work, but they also had a much more sinister purpose: human experimentation and the creation of biological weapons, chemical weapons, and explosives. Most of the people who worked were prominent scientists of Japan and were known to be in the Ishii's network. 
The biological weapons research facility at Pingfang was the most sophisticated of its kind at the time. Some facilities within the Pingfang facility included an advanced laboratory, two prisons (segregated on the basis of gender), two brothels (presumably with kidnapped "comfort women"), pool areas, schools, living quarters, stables for horses, libraries, administrative buildings, incinerators and crematoriums, and soldier barracks. Pingfang was heavily guarded, being surrounded by 3-foot electric fences and watchtowers. Ishii made sure that the activities in Pingfan were closely monitored and never released to the public.


The Imperial Japanese Army had told the local villagers in the area that the Pingfang Research Facility was a logging operation. Doctors within the facility referred to human experiment candidates as "logs," otherwise known as marutas. Maruta is a Japanese term for log. Most of these marutas were used as brutal experiments, including vivisection and biological weapons testing. 
When Pingfang was complete, other smaller stations were built in the surrounding areas and other occupied parts of Asia to complement the main facility. At the peak of his power, Ishii controlled aircraft groups, thousands of medical officers and other medical personnel, and many army divisions.

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