There was some discussions recently citing a lack online of official resources for the CBI theatre from a viewpoint of the involved non major power countries, Japan included.
This is the contact information for the Japanese National Defense Academy, which is the equivalent of the US Army Academy at West Point and the Fort Leavenworth C&GS College. Their Military History Department is the Japanese National Repository for all surviving military documents from the period 1921 to 1953.
National Defense Academy of Japan
Address: 1-10-20 Hashirimizu, Yokosuka, Kanagawa Prefecture 239-0811, Japan
Phone: +81 46-841-3810
Founded: 1953
Their official website offers little to military history research.
surviving source documents are held at the IJA and IJN Archive Holdings of the Military History Department. They can be viewed in person via pre- arranged escort into the College facility through their Public Affairs Office. Photostatic copies of micro-fiched documentation is available at a nominal fee per page in the viewing / research areas. I am not aware of any "proxy" arrangements that one can make for hiring / letting a research assistant such as one can arrange via the BundesArchiv for their fee. Military Historians and Historiographers must make their applications via the P.A.O. including major area of research. Translators must be pre - vetted by the P.A.O. for entry into the College and its associated archives as well.
The JGSDF, JASDF and JMSDF have no plans currently nor any budgeting for, a revelation / research assistance program such as we are now seeing distribution of photarchival items from the US Army's C.A.R.L.; the U.S. NARA, and the BundesArchiv. For now, the vast majority of surviving documentation will require some planning and coordination to gain access to.
Hope that helps those interested
KRL, Jon H