When we think about the atrocities done during WWII, we think of the Holocaust, Hiroshima & Nagasaki, or Nanking Massacre. Nevertheless, there is one special Japanese unit that was active in WWII that committed atrocities that will put any nightmare written in any horror stories to shame. The name of that infamous unit is “The Kamo detachment” or “Ishi Unit” but we usually know it as “Unit 731”.
As a special detachment of the “Kwantung Army” of Japan; Unit 731 operated from Zhongma fortress in Northern China. From here they carried out many biological experiments on nearly 3000 human test subjects for the purpose of “epidemic prevention research” but eventually those experiments were aimed at creating “weaponized diseases”. Before giving any details of some of those gruesome experiments, cautious advice that the following details can be graphic.
These experiments were conducted on mostly Chinese, Koreans, and several other prisoners of wars (POWs) and captured civilians. Weapons such as guns, bayonets, and even flamethrowers were used upon bound prisoners to see the impact of such weapons. Beyond that, they were crushed with heavy objects to see how much the human body can endure. Prisoners were forced to only drink seawater and also different human and animal blood were injected into them to see the clotting process.

Xinhua via Getty Images, Date unspecified.
One of the most common experiments was “frostbite testing”. During this, prisoners were kept in a freezing environment. Then the researchers used various crude methods to thaw out their frozen limbs. They tried burning their limbs, beating it with a cane, or just crushing it. Sometimes prisoners were forced to freeze to see how long the human body can endure the cold. Moreover, the researchers of Unit 731 never used proper anesthesia on their test subjects. They infected them with disease and then cut them open while they were alive. Afterward, they did research on the infected body parts such as the kidney, heart, and lung. Some of their limbs were cut open and then were reattached on other parts of the body. Some of their limbs were crushed or frozen to see the progress of the disease through their bloodstream.
While some people might think that these were brutal and enough but this is not the end of these experiments. Accounts of the unit’s activities have been built around many former member’s testimonies, photographs, and documentary evidence. From this information, it was known that they experimented with human fetuses. They did that by forcing the infected prisoners to rape the female prisoners and even male prisoners. It was done to see how those diseases can transmit from one another, especially through pregnancy. Unit 731 became quite desperate to produce “weaponized disease” at the end of the war. So they went with this “experiments through rape” more and more until a successful pregnancy happened. Afterward, they conducted more studies on the fetus or the babies. Keep in mind, none of the test subjects ever survived. If they somehow survived the disease, they were shot afterward. Prisoners of Unit 731 weren’t even called prisoners, they were called “Maruta”, or wooden logs in Japanese.
As for the fate of Unit 731, after the war, only a few of them who were detained by the USSR was persecuted. Those of them captured by the Americans survived any trials by handing out all their research in exchange. Later, the USA ignored most of the victim accounts of unit 731 as communist propaganda. Some of the Unit 731 researchers, like Hisato Yoshimura, who was in charge of the frostbite experiments, went on to have medical posts in public and private sectors in Japan.
Only in late 1990, Japan acknowledged the unit’s existence. However, they offered no detail about it whatsoever. A former nurse named Toyo Ishii of unit 731, said that she helped bury the remains of victims of Japan’s biological warfare program at a site in Tokyo, as US forces moved into the Japanese capital during the end of the war. According to her testimony, she and others like her were ordered to bury and destroy any of the paperwork or body parts of the biological experiments done during the war.
As of today, there’s so little we know about what happened and how much the people suffered in Unit 731’s prisoner’s camp. The hope is that people will acknowledge this atrocity even after all these years.