Unit 731 was a secretive biological and chemical warfare research and development unit of the Imperial Japanese Army during World War II. Led by Shirō Ishii, a microbiologist and general in the Imperial Japanese Army, Unit 731 conducted inhumane experiments on prisoners of war, civilians, and political dissidents. The unit experimented with various biological agents, including plague, cholera, typhoid, and anthrax, infecting human subjects to study the effects of the diseases and develop biological weapons. Shirō Ishii and his associates were responsible for the deaths of thousands of individuals and their actions during World War II are considered war crimes. After the war, Ishii was granted immunity from prosecution by the United States in exchange for his research data, and he continued to work as a researcher and businessman until his death in 1959.
