I’ve known it for a long time that PayPal provided the Japanese payment page but it’s recent I was able to duplicate the Japanese PayPal checkout page with my English version of web browser such as IE.

The trick is your browser needs to let PayPal know your language preference. To do that, you need to add Japanese to your browser’s Language options. If it’s IE, you can get to the option:

Tools -> Internet Options -> General

Click the “Language” button:

And, this is what you would see at the PayPal checkout: