I bought a sort of 'trick box' from an auction several years ago. The auctioneers didn't know how to open it, and neither did I really. They know something was rattling around in it, and figured it was money. I eventually figured it out, and I was happy to find that it probably belonged to an American GI during WWII. It contained a very old pack of Japanese matches, about 4 or 5 coins, and some paper money. I don't have the box with me now, but it and all it's original contents are safely packed away. Anyway, to the topic at hand, I found a 100 Yen note very much like this one: Mine is folded and creased, but mine is just like that one, if memory serves. Could anyone give me any information on this note? I know absolutely nothing about it. By the way, when I am able to get to the box again, I will try to post some pictures of the rest of the coins and bills that were in it. Also, if you'd like to know, I think I paid about 2 or 3 dollars for the box along with some other non-related stuff.
If your note is actually from WW II, the one you pictured is not the same. In fact you have shown a ¥100 Bank of Japan note initially issued on December 1, 1963, well after the end of the Korean War. In the Japanese Numismatic Dealers Association Catalog it's #11-74. In the condition you describe, its catalog value is no more than ¥200-700 ($1.70-6.00 at current exchange rates), depending on just how badly it is creased and how clean it may be. Japanese currency is hard to find in US coin shops, and when it does show up on EBay it generally goes for 25-50% of the JNDA catalog value.
Still very common, in fact in some auctions, some people still sell them in terms of 100s in original wrapping like this one: http://page6.auctions.yahoo.co.jp/jp/auction/f34939586 Even "rarer" is a hoard like this: http://page13.auctions.yahoo.co.jp/jp/auction/r37869125
Since I don't frequent the paper money section, I probably would have never seen the posting (or IDed the note) if it had been posted over there. At least without some indication in the title that the question was about a Japanese item.
Sorry for taking so long to reply, but I've been busy for a while. I'm certain that the note is from the WWII era, and that is was a 100 yen note. I think it also had a bearded man. Does anyone know what the note could be?
If you are talking about the same note, no it's not from WWII. Do check this site for more infomation: http://aes.iupui.edu/rwise/countries/japan.html