Looks like buying digital from the Japanese store is getting much harder. Yesterday my 360 arrived, and I surfed around trying to buy a prepaid gift card to absolutely no avail, since the transaction would decline every time. I emailed one site's support team to ask why, and he said my account had a security concern - To resolve it, I would have to send a selfie with my real ID (!!) among other things. Just look at the email:

That's g2a, who are known for being shady, but I soon discovered the same for seagm:

These are only two sites I explored, but the others probably blocked it for the same reason. I would encourage everyone NOT to give their ID to these websites under any circumstance, so now we have the additional problem of getting ahold of Japanese cards at all. Luckily, you can probably still just transfer money into your Paypal from your bank, and use the Paypal wallet successfully since it's not drawing funds from a card, but this change still prompts concern in any event, and maybe it's even worth contacting CAVE and others to see if they could put the games on other 360 stores, or port them to Windows if not. It's crazy having a bunch of people who want to buy a game legally, but can't because region lock makes it impossible.