Unit 731 of the Japanese Army conducted some of the most heinous experiments in the human history on POWs during the World War II. Unit 731 had eight divisions: Division 1- Bacteriological research; Division 2- Warfare Research and field experiments; Division 3- Water Filter Production; Division 4- Bacteria Mass production and Storage; Division 5- Educational Division; Division 6- Supplies Division; Division 7- General Affairs; Division 8- Clinical Diagnosis.
The leader of this unit was a 6-feet tall man known as Shiro Ishii. Born in Japan, Shiro was a bright young man who studied at the Kyoto Imperial University. There, he got to study preventive medicine, pathology, serology and bacteriology. In 1922 after completion of his studies at Kyoto Imperial University, he was sent to Kyushu where they were battling a contagious disease which was aggressive and causing deaths of many people including soldiers.
Shiro studied how he could effectively filter the contaminated water. He was able to successfully do it, much to the acclaim of his colleagues. To prove his filters worked to the Emperor of Japan, he demonstrated how his device worked by filtering his own urine and drinking it. In 1928, Shiro Ishii traveled extensively in various countries learning from their clinics and laboratories. After two years of travel, he returned to Japan. Due to his close association with influential and prominent officials, he was able to secure funding for his projects which he believed would propel Japan to the world leadership.
Shiro Ishii proposed a research unit to study biological and chemical weapons. He argued that the Western powers were carrying out similar programs. He got support from Colonel Chikahiko Koizumi who was the army’s Surgeon General (later become Japanese Health Minister) and had secretly joined a poison gas research committee during World War I.
Shiro Ishii was given the command of Unit 731 in 1932.
The project Unit 731 aka Epidemic Prevention and Water Supply Unit of the Kwantung Army, was initially established in Harbin. This was later to be blown up by prisoners and they had to look for a new location. Due to the kind of experiments being conducted, secrecy was a priority. Manchuria was a perfect hideout place. Manchuria was forcefully taken from the Chinese through Japanese invasion. It was about 200,000 square kilometers. In Manchuria, the research facility was set up in Pingfan and occupied three square kilometers. The buildings were strategically built to hide any suspicion and were further shielded by high walls and high voltage wires.
Later on from 1937 after Japanese expansion to China, other such facilities were set up in various Chinese cities such as Hsinking, Guangzhou, Beijing, and Nanjing.
The opportunity to work at the Unit 731 facilities was highly appealing to doctors and scientists as they the chance to experiment on human subjects and had financial aid from the army. To work here required high-level secrecy and members of the unit had to be transported in covered cargo trucks whose registration numbers were often changed to conceal identity. Some staff knew what was going on while others did not know of the “death blocks” where prisoners would pass through never to return. By 1939, Ishii’s network comprised of over 10,000 personnels conducting research at Unit 731.