I was wondering where can I find digitised versions of Japanese war documents in original Japanese?
I can read Japanese but I cannot seem to find any primary sources that relate to the Japanese army in ww2
Any help much appreciated
Don't know how helpful this is, but I think the real question you want to ask is whether or not there are documents publicly available concerning the Japanese military from World War II. Many such documents, especially official records concerning various crimes against humanity, (i.e. The Nanjing incident, Bataan Death March or the Bangka Island Massacre in Indonesia read at your own risk) were likely destroyed or hidden at the end of the war.
It is difficult to tell whether surviving military records could be accessible. My bet is that this type of research is best conducted on site. In other words by visiting Japan.
Your first port of call is the public archives of the victors, particularly the records of military trials:
http://discovery.nationalarchives.gov.uk/SearchUI/Details?uri=C11603634 http://discovery.nationalarchives.gov.uk/SearchUI/Details?uri=C3040467 http://discovery.nationalarchives.gov.uk/SearchUI/Details?uri=C4408406 http://discovery.nationalarchives.gov.uk/SearchUI/browse/C14441
And of course, the archives of the inheritor state: http://en.wikipedia.org/wiki/National_Archives_of_Japan
You may wish to contact professional historians, or if the archives supply direct copying services, the archives. This may get very expensive.
There may also be "sourcebooks" of historical documents printed in Japanese on war events. I would suggest that due to the politicisation of Japanese military actions in WWII in Japan (the chief reading public for Japanese), that such sourcebooks would be primarily produced by the side of politics that reviles Japan's war past and seeks to more firmly cement a discussion of this past in national life. Sadly, not being a Japanese speaker or historian, I lack the interlingual googlefu to find such works at amazon.co.jp or in the national library of Japan.
The Diet Libary seems to have some holdings: http://iss.ndl.go.jp/books?any=%E6%A5%B5%E6%9D%B1%E8%BB%8D%E4%BA%8B%E8%A3%81%E5%88%A4 http://iss.ndl.go.jp/books?any=%E6%97%A5%E6%9C%AC%E3%81%AE%E6%88%A6%E4%BA%89%E8%B2%AC%E4%BB%BB%E8%B3%87%E6%96%99%E3%82%BB%E3%83%B3%E3%82%BF%E3%83%BC
Perhaps the best online collection of Japanese wartime documents, in Japanese, is found at JACAR, or Japan Center for Asian Historical Records.
This contains a large body of documents from the national archives, the foreign ministry, the archives of the ministry of defense, and some other materials.
Given the mission and founding of the project, the collection is particularly strong in World War II materials. You will find that many of the documents can be short, and difficult to understand out of context, so be sure to read up on the collections and perhaps some Japanese secondary sources on the structure of the military etc. to help you orient yourself in the collection.