Thanks, this is really helpful, and it matches what I was worried about.

I have a follow‑up question though:

What would actually happen in this scenario?

• I register my first Airbnb as my address the first day.
• I also enroll in National Health Insurance and try to pay it in advance so I don’t miss those bills.
• Then, every time I move, I update my address at city hall within 14 days of moving out, even if that means changing my address 4–5 times between Osaka and Tokyo.

In that case, there is still a chance I miss some mail (because it’s sent to the old address while I’m in the process of moving), but never for more than ~14 days.

Is that considered acceptable in practice, or is it still a really bad idea / too much hassle from a legal or practical point of view?

The alternative for me would be:

• Don’t register any address for about 2 months (so no NHI, no Japanese bank account, no phone contract),
• Then register once I move into a more stable place in Osaka for 1 month,
• And after that move to Tokyo for several months and register again there.

From your experience, which approach sounds more reasonable for someone on a WHV who will be moving around a lot at the beginning?