[4hg4ufxhy]

If you have a permanent residence permit in Japan you need to file their taxes annually even when living abroad.

In Finland you have to live abroad for 3-4 years until you are not taxed anymore.

[jalapenos]

The permanent resident permit concerns immigration, not the tax office.

The tax office cares if you have a domicile ("living base") in Japan or possess a residence there for over a year.

Not a tax professional.