Earlier quoted context omitted.
It's more about taxes. If you apply for a working visa you can be flagged as having revenue generated while in the country, so you'll pay an income tax on it. The other side of it is visa overstay: it's more financially viable for working people to overstay their visa, where pure tourist have to go back at some point. Terrorists will be flagged whatever they do, as international money transfers are already heavily sc…
Any idea of how much the tax might be in Japan? And how does it affect taxes in the US?
https://www.nta.go.jp/english/taxes/individual/12006.htm
I didn't go through all of it, but I'd expect it to be a tad less that 10% of the gross income.
If you're a US resident, I think you pay them as well on that same income ?