If you're looking for scholarly studies of Japanese history, literature or culture, start with the library catalog (Cameo) and databases such as MLA (language & literature), LLBA (linguistics), Historical Abstracts, Google Scholar, full-text journal collections such as JSTOR and Project Muse, or reference works such as Credo Reference, Literature Resource Center or Oxford Reference Online. The most comprehensive index to use for citations to books and articles is the Bibliography of Asian Studies.
See also the East Asian History guide.
Be sure to consult General Tips for Finding Resources in Different Languages on the Modern Languages guide home page.
Many primary sources on Japanese literature and culture can be found at websites such as these: