Hi Paul, I have to agree with Satsuma. I don't think it is Japanese, many times what collectors see in pictures are not boonie hat's but crushed pith helmets. At any rate, if it were Japanese it should either have a square ink stamp with the date, maker, and possibly a name if it was army. Or one or two square white labels sewn in for Navy. This is a "safe" generalization or guideline for Japanese cloth and cloth headgear. Take care and glad to see your doing well, feel free to PM me on your Japanese finds, this was my first love before I got poor and went to Iraqi stuff. Scott.