This has been an issue for Japanese adult game developers for a while now. Here’s an article from the same site from 1.5 years earlier that provides a bit more context. It seems like there’s either confusion or perhaps malicious misinterpretation of Japanese laws going on.

I wonder if they could somehow open a bank account in the US or somewhere else outside Japan, get the proceeds from their games sent there, and then transfer from one bank to another, or as a last resort even going in person and transporting the cash by hand.