"Among the heathen we shall find no others that surpass the Japanese in manners!!" - - St. Francis Xavier.
That treatment of allied prisoner-of-war [POW] as captured and interned by the Japanese during World War Two [WW2] often a subject of commentary. Captives numbering in the hundreds of thousands [combining allied military and civilian both] the death rate about 50 %. Those perishing from a combination of ill-treatment and brutality, often downright murder!
Such Japanese conduct in previous wars NOT BEING THE CASE.
From the book "Flyboys" by James Bradley:
1. The First Sino-Japanese War .
"We command that our subject make every effort in the performance of their official duties to ensure that international law is not transgressed." - - Emperor Meiji.
2. The Russo-Japanese War .
"Meiji's . . . declaration of war against Russia had included a similar injunction . . . During the war 79,367 Russians were taken prisoner. they were detained in 29 POW camps throughout Japan and were well treated . . . After the war ended all the POW's were safely returned to Russia."
3. World War One. [1914-1918]
"We command all our competent authorities to make every effort in pursuance of their respective duties to attain the national objectives within the bounds of international law."
JAPANESE BEHAVIOR IN ALL PRIOR INSTANCES CORRECT! EVEN TO A FAULT!
So what happened in that period leading up to and during WW2? I leave that to the historians to decide.