I know that Unit 731 were given an amnesty for the results of their unethical research, but what about everything else, like the Rape of Nankin, Rape of Manila, Bataan Death March, Death Railway, Comfort Women, the sinking of australian hospital ship AHS Centaur, the beheading of POW et caetera? Were any Kempeitai sentenced like the Gestapo?
To a limited extent. There were the Tokyo Trials. But many, such as Ishii, were never prosecuted. I don't recall the Kempeitai being charged en masse like the SS, even after it was disbanded.