There are a lot of objectionable Japanese occupation policies in Asia, some of these are the medical experimentations, the infamous Bataan Death March, and the killing of prisoners of war.
It was known that Japanese conducted an experiment to the prisoners, mostly from Korea, like injecting sea water. This was just a speculation since no evident was uncovered, but a lot of those who survived testify.
The Bataan Death March or the March of Death was also one of the infamous objectionable policies they conducted in Philippines, forcing the prisoners of war to march an estimated 66 miles or 106 km.