Japan does have a serious population problem, think I read somewhere they are willing to give lots of money for people to go live in the country.
They need a major shake up in the way they do things and soon.
No they're pretty anti immigrant and might chose to become irrelevant over importing lots of people . I think they should do something like what the gulf countries do and import workers but not give them citizenship. But a uniquely japanese way of solving the problem might just be to use robots and automate all that can be automated.