During World War II, the Imperial Japanese Army had a unit that studied germ warfare and biochemical warfare, officially known as the "Kwantung Army Epidemic Prevention and Water Supply Department", commonly known as "Unit 731", or the Manchurian 731st Unit. This force is notorious because they engaged in various unusually brutal human experiments with living people during the war, resulting in the deaths of at least three thousand people.
The 731 unit of the Japanese army was originally responsible for the epidemic prevention and water supply operations of the front-line troops, shouldering the heavy responsibility of reducing the incidence of epidemic diseases, so it was called the "epidemic prevention and water supply department". But at the same time, in addition to "defending", this unit is also responsible for "attacking" - that is, dropping germ weapons on the enemy, hoping to reduce the enemy's combat effectiveness by spreading disease.
After the First World War, countries signed the Geneva Protocol in 1925, prohibiting the use of biological and chemical weapons in war, but the development, production, storage is not limited, Unit 731 is the Imperial Japanese Army's research institute for biological and chemical weapons, but on the Chinese battlefield, the Japanese army often illegally uses the bacteriological weapons of Unit 731. Even more terrifying is that they used prisoners of war with Chinese, Koreans for bacteria, venereal diseases, weapons, various live experiments and even vivisection, becoming the largest and most brutal biological and chemical weapons development base camp during World War II, and even the Japan Broadcasting Association (NHK) has produced a documentary about the existence of Unit 731.
After the Soviet Invasion of Manchuria on August 9, 1945, Unit 731, in order to avoid being discovered, blew up all the relevant facilities with a large amount of explosives, killed all detainees, and took away a large amount of information, so that most of their criminal evidence disappeared, resulting in the crimes of Unit 731 have not been completely liquidated, and many members even entered medical schools and hospitals after the war. However, there are still scholars who hope to find clues to the crimes of Unit 731, and Katsuo Nishiyama, an honorary professor at Shiga Medical University in Japan, found on June 19 that the Japanese government made official documents after the war, which not only recorded the organizational structure and members of Unit 731, but also their actions before and after Japan's defeat, and the first time found evidence that Unit 731 did produce bacteria.
The Kyoto Shimbun reported that Katsuo Nishiyama found a total of 41 official documents produced from 1950 to 1951, "Overview of the Units of the Kwantung Army's Epidemic Prevention and Water Supply Department", in a document published in March this year. It can be seen from the official documents that there were five branches of this unit at that time, of which the Dalian branch stated in the official documents that "until the end of the war, they were the main force responsible for bacterial research and production." As for the other four branches, Linkou, Mudanjiang, Sun Wu, and Hailar, there are "detailed investigation tickets" that record the names and ranks of the team members. The documents also include a table of changes in the various branches, as well as a map of the trajectory of the movement before and after the defeat (the main map of the action group), and even the location and date of the battle are also detailed.
After Japan's defeat, some of the team members became prisoners of war of the Soviet army, and this document also has information about soviet shelters. According to this information, until 1951, there were still 3262 members of the Kwantung Army's epidemic prevention and water supply unit, including the testimony of members of Unit 731, which is of great historical significance. However, the information released by the government this time does not have the "detailed investigation ticket" and "action group through the key map" of the headquarters of the 731 unit and the Dalian branch, and Nishiyama Katsuo pointed out that if he waits for the government to slowly declassify and publish, it will become more and more difficult to interview and investigate those who are still alive. He called on the government to speed up the declassification, so that historical and medical researchers, such as the "15 Years' War and the Japan Medical Research Association," could work together to continue the investigation.