The National Consortium for Teaching about Asia also proves to be a valuable website to find resources about East Asia. This website is designed for educators. It is a multi-year initiative to encourage and facilitate teaching and learning about East Asia in elementary and secondary schools nationwide, it is a provider of professional development. Teachers have the option to register for online courses or take a course, which seem to be offered around the nation.
The website also includes a list of Resources which I found the most useful. One of the links included in this website that I found really helpful was the Center for Asian Studies: University of Colorado Boulder (http://www.colorado.edu/cas/tea/becoming-modern/) This website offers a wide range of primary sources for teaching about Japan in the early 20th century through primary sources. Including a Case study on the United States and Japan, 1905 and 1933. I would recommend this site to teachers teaching World History.
http://nctasia.org/resources/