The National Institute of Science and Technology · Academic Policy (NISTEP) conducts every 3 years a „Survey on employment and career of postdoctoral fellows. The FY 2015 results, just published, show that among 15,910 postdocs, the number of Japanese was 11,465 (72.1%), of foreigners 4435 (27.9%). 70 % of foreign postdoctoral fellows come from Asian countries such as China, Korea, and India. 5812 postdocs (36.5%), worked in science, followed by engineering (22.2%), health (16.2%), agriculture (8.7%), and the humanities (7.7%). The absolute number of postdoctoral fellows has been declining from a peak of 17,945 people in FY 2008. It seems that young people have noticed the fact that even if they become postdocs, it is unlikely that a happy future will be waiting.”
NISTEP report, February 14, 2018