Do you think Japan is a viable destination in terms of career and general living standards for a European couple (AI researcher + welding/nuclear mechanical engineer)

My partner and I have been moving across Europe (we are from an EU country) trying to find a place to settle, we have not found our home yet. We are currently based in the UK, but feel like this wont be the place to settle either, so once I finish my PhD we would move on. I have been fascinated by Japanese culture, although I have never been. Currently being torn between the US (salary is a big plus, but cultural and health issues are putting us off) and Japan (I am aware wages are not great, and the work morale is demanding). We have just started researching and I thought I would ask for personal experiences here.

Is Japanese society welcoming, is it hard to fit in for europeans?
The country is decently placed on the quality of life index, but I wonder what this means in practice. The property price to income ratio is even higher than in the UK (the UK is catastrophic in practice) which is worrying, but I think these indices are not always in line with reality, so… What do you think, is it a viable career option for engineers and researchers?

Edit: we don't speak Japanese.