How did the japanese often treat the native people of east asia and their prisoners of war in territory they conquered?

The Japanese were very brutal toward the people in East Asia that they conquered. Similar to the Germans, and even worse in certain aspects, the Japanese treated the conquered people as lower human beings, as not worth of living, as primitive. The rate of sexual assaults that happened was extremely high. People were tortured, murdered for no reason, and used as slaves. The Japanese even went so far that they allowed their scientists to test certain chemicals on the conquered people and to see if they can be used as weapons of mass destruction, leading to the death of hundreds of thousands, or maybe even millions.