"Rational Choice Analysis and Area Studies: enemies or partners," by Margaret A. McKean in Neil Waters et al., ed., Beyond the Area Studies Wars, University of New England Press, 2000, pp. 29-63.
The author attempts to help uncover how to find these critical documents by describing the Japanese policy making process, along with the life-cycle of these documents at each step. The author believes there are two major fundamental changes that must be made to improve access to Japanese government documents; (1) an enforceable records management system must be established across the government, and (2) a legally mandated open government mechanism must be created.
Grey literature includes publications "produced at all levels by government, academia, business and industry, both in print and electronic formats, but which is not controlled by commerical publishing interests, and where publishing is not the primary business activity of the organization." These provide important but difficult to find research materials.
These are the three most important journals in Japanese Political Science which Duke subscribe to. Searching MagazinePlus while limiting your search to one or another title will help you assess their relevance to your interests.
Developed by Leonard Schoppa at UVA, it is a comprehensive source on contemporary Japanese politics. The links pages are excellent.
Japan Focus presents writings about Japan, Japan in Asia and the world, as well as Japanese and international perspectives on contemporary Japanese politics, economics, society, and culture. It offers translations from Japanese, reprints of important English language texts, and Japan Focus originals. A subscription link to their weekly newsletter is available on the website.