It's starting:

https://automaton-media.com/en/news/japanese-game-and-comic-platform-dlsite-launches-its-own-payment-alternative-following-visa-and-mastercard-suspensions/

DLsite is the biggest platform for hentai that I know of. If something exists, it's probably being sold through there. This is pretty likely to work out for them and maybe other japanese sites can use it as well.