My grandfather would probably mutter something about how "you sleep in the bed you make." People have been calling this for more than a decade, but Japan would rather watch itself die than to encourage immigration (or, God forbid, enact changes to encourage a domestic population growth).
This isn't limited to the big evil capitalist politicians, either. Xenophobia exists across almost all layers in Japanese society across the country.
I agree too. The fact is that our planet is simply fucked if we keep this ever urge for growth. It's not sustainable and the cracks are clearly showing.
People don't want to hear it but we should have a max 1 child limit per couple for at least some years or encourage people not to have children at all. Then when we've reached a healthy sustainable population have a 2 children max limit.