Unit 731

Unit 731 was a downright sadistic and sick experiment performed on several prisoners of war in 1935 to 1945 by the Imperial Japanese Army. These experiments researched the reactions that humans include when exposed to several chemicals.

In the experiment, he had several political activists, prisoners of war, and just random civilians picked to be the subjects. These subjects included adult men, pregnant women, children, and even infants. The experiments then began, these including: Though it was done in the name of scientific research, the actions performed in Unit 731 were far too inhumane and sickening to not be antagonized.
 * Infecting them with various chemicals
 * Cutting them open when they were awake
 * Dismembered them and sewing their limbs back on when they were awake
 * Having their organs (such as their stomach or brain chunks) removed and installed in different places
 * Having them violently raped and infected with STDs to "study" the effects
 * Tied to poles and used as target practice for weapons such as chemical grenades and flamethrowers