Just tell the unemployed to leave. I guess if all unemployed people left, then the unemployment rate would in fact be lowered. The program applies to foreigners of Japanese descent and the way it works is that the government basically pays you to leave. The fine print states you can't return to Japan unless the economy gets better. Ouch. This would absolutely never fly in the US.
Oh and Japan, with a shrinking population as it already stands, it may not be the best strategy to encourage even more people to leave.