Non-US Paypal account doesn't work on Appointments+ ?

I'd like to make sure that if it's possible to use non-US Paypal account in appointments+ plugin.

My client just created his Japanese Paypal account but it doesn't work on the site. http://nobuhirosato.com/bizportal/check-schedule/

The site is based on English Wordpress but the site only targets Japanese customers.

I tested with my English Paypal accounts (business/personal) and they all worked well.

Thanks,