Thats the way it is when youre trying to dehumanize your enemy in order to make killing them easier.Based on some of the things I've read, I'd say the Japanese did a pretty good job of dehumanizing themselves.
Forced slave-labor, prisoner attrocities, etc. They were the ones wildly mistreating their enemies, both soldier and civilian.
Oh, some of them were absolute MONSTERS, particularly Japanese Unit 731 and the rape of Nanking.