We all know of the often terrible treatment that Dutch, British, Australian, and American POWs recieved as prisoners of the Japanese military in the Pacific.
But if memory serves me correctly, the reason that the Japanese treated their POWs so horribly is that the prisoners did not deserve respectable treatment because they had surrendered instead of killing their enemy until dead, or committing suicide. Much like how the Japanese soldiers were taught.
If the Allied prisoners did not deserve respect, according to Bushido tradition, why would the Japanese even bother taking prisoners, unless to use them as bargaining chips, or to use as hostages against Allied bombings?
What else would they do with them... there's either kill or allow to go? Don't think either would have served Japan's military's interest very well.