Japan only requires leaving for converting a tourist/digital nomad visa and some Working Holiday Visas to a normal working/spouse visa. And WHV to normal status is really dependent on the partner country. For example Australians don't need to leave, but Canadians and Brits do, and I've heard that immigration will sometimes just grant the change of status anyways. So that seems to indicate that Japan doesn't really care.
Needing to leave to convert a normal working/spouse status to PR is not the norm anywhere.
Needing to leave to convert a normal working/spouse status to PR is not the norm anywhere.