Payment system seems to just be standard credit card stuff, so it's mostly an IP thing where if you access from outside of Japan, the program 'won't be available in your region'. You might be able to work around it with a VPN if you wanted.
The coin purchase screen.
Konomi Suzuki and Da-iCE also have lives pay per view and Da-iCE's is locked but Konomi's is available overseas it looks like. I wonder why they'd lock it if the option to open it up is there.