I think when reviewing Japanese WW2 figures that the Japanese Warrior Cults that figured heavily in military training at this time believed it was honourable to die for one's country is a major factor in this. The Japanese soldiers were prepared to fight to the last man at all costs. Indeed it wasn't that long ago that they found an old Japanese soldier that had to be convinced the end of the war was not an Allied Propaganda trick...
WW2 Japanese soldiers were the original creators of Jungle guerrilla warfare with all sorts of hidden tricks which influenced some of the Viet Cong tactics during Vietnam...