The Iwakura Embassy, 1871-1873 by 
Selected Works of Mao Zedong by Materials that we generally think of as secondary sources--such as scholarly journals--can be used as primary sources if your aim is to closely examine a debate or conversation during a specific time period.
Here are some examples:
Remember, too, that JSTOR includes the deep backfiles of hundreds of scholarly journals. Suppose, for example, you'd like to see if/how American scholars in the 1930s were writing about Japan. By using the advanced search interface in JSTOR, you can limit your results to just articles from the 1930s and would discover that the journals Pacific Affairs and Far Eastern Journal provide numerous articles for examination.
An interdisciplinary journal archive. It includes archives of over one thousand leading academic journals across the humanities, social sciences, and sciences, as well as select monographs and other materials valuable for academic work. Includes the Artstor image collections.
Government documents can be rich primary sources. A few highlights:
Sources in Chinese History: Diverse Perspectives from 1644 to the Present by 
Sources of Chinese Tradition, 2nd ed. by 
Hawaii Reader in Traditional Chinese Culture by 
Sources of Japanese Tradition, 1600 to 2000 by 
Modern Japan: A History in Documents by 