If we accept their false premise that the country will be destroyed without foreign labor, then temporary workers with no opportunity for future immigration would be fine.

Yes, I agree, but for that this was what was tried in Europe with 'guest workers'. But then they demanded citizenship, and that was what the elites wanted to begin with.

(Also need to make sure if a foreigner male gets a Japanese woman pregnant, the child is not given Japanese citizenship and must go home with the father. The woman can leave too. This is to prevent anchor babies.)

Ius sanguinis is the best ius.