Very sorry for the delay @esren , we missed this one as it should have been replied to right away.
Japan numbers do not have SMS unfortunately, some institutions allow for verification through a phone call, for example whatsapp business - so we know that should work fine.
Even with our SMS enabled numbers, we cant guarantee verification texts - mostly due to the fact the companies themselves won’t sent the text to the virtual phone number.
Again this is not absolute, for example, we’ve seen verification texts work pretty well for Israeli mobile.
This won’t be required, our local Japan national 81-50 numbers will require proof of address anywhere in the world.
Let me know if you have any other questions or concerns.