For an opinion piece on public and private universities in Japan, teaching and learning culture and job stability, see this piece in the Times Higher Education by Susan K. Burton (associate professor at Nagoya University of Commerce and Business from 2003 to 2009 and at Bunkyo Gakuin University from 2009): http://www.timeshighereducation.co.uk/features/beyond-sushi-the-attractions-of-lecturing-in-japan/2008873.fullarticle
Japan Society for the Promotion of Science
CareerCentral are developing a good relationship with JSPS (Japan Society for the Promotion of Science). Look out for their return to campus. This body provides a summer programme and post-doctoral fellowships (from 1-12 months, or 12-24 months) via The Royal Society, The British Academy and the British Council Tokyo, and is relevant to researchers from all fields, including the humanities and social sciences, as well as the natural sciences. Placements or fellowships typically include: air fare, travel insurance, maintenance and research allowances.
JSPS Summer Program (pre- and post-doc)
http://www.jsps.go.jp/english/e-summer/ (For citizens of the US, the UK, France, Germany, Canada or Sweden) and see http://www.britishcouncil.jp/en/programmes/higher-education/support-researchers (UK citizens only). The JSPS Summer Program is implemented as a component of the JSPS Postdoctoral Fellowship for Foreign Researchers. It provides opportunities for young pre- and post-doctoral researchers from North America and Europe to receive an orientation on Japanese culture and research systems and to pursue research under the guidance of host researchers at Japanese universities and research institutes over a period of two months during the summer. The 2016 Summer Programme application period will open in the autumn of 2015.
Postdoctoral Fellowships for Foreign Researchers (including pre- and post-doc routes)
http://www.jsps.go.jp/english/e-fellow/ .To promote international scientific cooperation, the Japan Society for the Promotion of Science encourages highly qualified researchers from the world over to come to and conduct joint research activities with colleagues at Japanese universities and research institutes.
Applications close round about February. For details of 2016 scheme, see:
The Royal Society (SCI/FMH): https://royalsociety.org/grants/schemes/jsps-postdoctoral/ (UK & EU citizens)
British Academy (HUM/SSF): http://www.britac.ac.uk/funding/guide/intl/jsps.cfm (UK citizens)
The United Nations University (UNU)
A global think tank and postgraduate teaching organization headquartered in Japan, with global postings. It is an academic and research arm of the UN. Offers employment, internships (some in Tokyo) and fellowships, including individual contractor/consultant positions.
jrec-in (jobs portal)