CNS Co., Ltd. is an enterprise that supports all marketers.

Here are some "useful" websites for your reference in Japan.
When you are looking for some basic and credible data/statistics for Japan and its market, you may find these websites below are quite useful!

Statistics/Census of Japan (e.g. population and households data, etc)
http://www.stat.go.jp/english/data/index.htm

"Economic and Financial Data for Japan "
http://www.stat.go.jp/english/19.htm

Economic Statistics and reports by Cabinet Office of Japan
http://www.esri.cao.go.jp/index-e.html

Automotive Marketing database
http://jamaserv.jama.or.jp/newdb/eng/index.html

Telecommunications Carriers Association(TCA)
http://www.tca.or.jp/english/database/index.html

Japan Electrical Manufacturers' Association(JEMA)
http://www.jema-net.or.jp/English/report/index.html

Japan External Trade Organization(JETRO)
http://www.jetro.go.jp/en/reports/

Statistic of finance (household income/paid tax amount, etc)
http://www.nta.go.jp/kohyo/tokei/kokuzeicho/gensen2002/02.pdf