Still Japan has a huge guest worker program that seems to get the help they want, or need, in certain occupations. I know being an island helps them.
There are many islands whose immigration policies I wouldn't want to adopt.
The point is that Japan-until recently-took immigration seriously.
The Japanese didn't allow millions of immigrants-from distinctly foreign cultures, who would not be able to assimilate-to live there.
To the extent that a guest-worker program is effective in Japan it's only because Japan takes this problem seriously, although even the Japanese are becoming lax, in imitation of their American allies.