Useful databases:

• Blackwell Reference Online
• Bibliography of Asian Studies
• Anthropology Plus
• Sociological Abstracts
• Alexander Street Press - All Discipline Search
• Refworld - (UN High Commission on Refugees)
• ProQuest Dissertations & Theses Global

Newspapers:

• Japan Times Archive, 1897-2014
• Factiva  (recent 2 years)   
• Asahi Shimbun Asia & Japan Watch (AJW)
• Historical Newspapers Online  
• Access NewspaperARCHIVE  

Some Useful Subject Headings (Control vocabularies) in Quick Search, Article+, Orbis or WorldCat: 

• Aliens -- Japan
• Immigrants -- Japan 
• Japan -- Emigration and immigration
• Ainu -- Religions (Rites and ceremonies,  Social life and customs, etc) *
• Buraku people
• African Americans—Japan
• Koreans—Japan  (Or, Chinese, Philippines, Brazilian, Peruvian—Japan, etc)   
• LGBT--Japan
• Sexual minorities -- Japan
• Emigration and immigration law -- Japan.
• Japan--Ethnic relations 
• Okinawa-ken (Japan)—Civilization

* If you find more specific subject heading after a large heading.  For example, -- History,  Social conditions, -- Languages, --Attitudes, -- 20th century, etc.

** Also, you can further divide by source type like “interviews”, "periodicals", “statistics” and “Pictorial works" in Subject Headings.

*** Be creative to come up with other keywords such as: Zainichi.to discover other subject headings

Statistics: 

• The Ministry of Justice home page
• e-stats
• Statistics Bureau
• http://guides.library.yale.edu/aecontent.php?pid=87561&sid=669568

Guide for citation management (Refworks, Zotero, EndNote and Mendeley):

• General: http://guides.library.yale.edu/citationmanagement
• Citation guides for East Asian Languages: http://guides.library.yale.edu/eas-citations

Other Useful databases/guides:

• LGBT Life with Full Text
• ATLA Religion Database
• Japanese primary sources in Western Languages
• Guide about scholarly works and peer-review works by U. of Toronto