Japan's WWII atrocities were worse than the Nazis' but covered up by the American government in exchange for the research.
Cholera, anthrax, bubonic plague & other bioware agents were created & used in Imperial Japan's attempt to rule Asia.
Unit 731 was an infamous horrific research facility in Harbin China. What's hardly known is there were 4 other facilities like it in China.
Japanese don't learn about any of this in their schools & the government still officially denies what they did just 75 years ago.