Is Japan a vision of the future of the US and Europe were it not for immigration?

The FT this morning had these sober numbers describing Japan, which show plummeting number of 20-year-olds and eroding monthly earnings.  Without immigration, Japan's present would be Europe's and North America's future.  Japan, however, would rather shrink in many ways than change its culture.

See "Deflated Generation": http://www.ft.com/intl/cms/s/0/1b24264e-b9d8-11e5-bf7e-8a339b6f2164.html#axzz3xEevmhh8