@pwim I think there is this $50.000 investment visa option. So, theoretically, if you have $50.000 spare money. You could establish a company in JP and apply for that visa by investing in your company. But, I have to admit that I’m not 100% sure if that works like this.
On the other hand, @4ydx, I think the two options you have listed are basically the same. When companies have outstanding tasks, they are either hiring employees or paying another company to do the work. As a contractor, you basically establish your own company. Then you sign a contract with the company and issue invoices regularly which the company pays. Depending on the country where your company is established, you could pay out from your company’s bank account different kind of monies into your own pocket. I personally operate in this construct (but not from JP), and I have a monthly minimum salary & pay out dividends. Of course, both payouts have their own consideration in terms of taxes.
Anyway, going back to JP, in case you have an established (remote contractor-) business, you could live in JP. But, of course, there is a catch. First of all you would have to go to business-orientated letting services from which you could rent. Normal landlord demand a visa, I suppose. So, you could rent easily from business-orientated letting services, but because these business-orientated services do not plan in the long term with their tenants, renting a room will be expensive and way above the average rent on the open market. The second catch would, that you would have to leave JP every 180 days (or 90?) and re-enter so that you get a new tourist-visa.
And yes, you would basically break the law because you would work with a tourist-visa. But that is something you would have to make up with your own conscience. You can check out Digital Nomads and what they do about this when traveling to & working from other countries.
Anyway, this tactic might be an option to live for 6M-12M in JP - Which might be already enough for some people to gather some experience?