Check out the Gaijin "bonus" for leaving Japan!
About the J-Pension Refund...
There is a Y590,000 limit on the refund so if you have paid lot of money into the Japanese Pension system having the 11 years you paid into the J-Pension transferred into your UK-Pension program is a better deal (if the UK and Japan have that pension swap).
On the other hand, for folks who mostly worked "off the books" doing freelance work, hostessing and the like during their stay, the J-Pension Refund will be a good deal just as it is for 3-or-fewer-years gaijin. (The very name of the pension-refund scheme in Japanese refers to payments for "short-term" foreigners--the 90 percent who leave within three years.)
The Irish Net Nippon presents Everything You Ever Wanted To Know About The
JAPANESE PENSION REFUND SYSTEM
Adapted from an article originally published in the Japan Times.
[[ a bit old, but still valid]] >Q. What if I have more questions?
A. In Japanese, call the government offices mentioned earlier where the pension payment application will be distibuted and ask to speak to someone who can tell you about pensions (nenkin). Specifically, ask about lump-sum withdrawal payments for foreigners (tanki zairyu gaikokujin ni taisuru dattai ichijikin.)
Also be aware of this possible refund...
I don't know if I would trust these folks with my money, but they do seem to have a "method" to get both the: "1. The pension refund itself (below) 2. The additional 20% tax refund."
[url=] Tax Representative Service Pension Refund[/url]
See the old threads
Pension & Health Insurance payments