Japan's Perception of Other Asian Countries and POWs
The Japanese considered all other races to be beneath them, and treated them as such. Since other Asians were considered to be "lower forms of life", Japan's biological warfare team had no qualms on human experimentation. Similarly, surrender was regarded as dishonorable, so POWs were subject to the same brutality. The Japanese also disliked the Europeans that colonized Asia, because they believed that "Asia was solely for Asians" and not for inferior European people.
"Japan’s ultra-nationalist factions believed it was Japan’s rightful place to rule over Asia and that the Japanese were a sacred and pure race whose duty was to “liberate” other Asians from colonial rule."- John W. Dower, author of War Without Mercy: Race and Power in the Pacific War