When proceeding to the PayPal screen for payment, you will be presented with the option to login to your PayPal account. However, you may also choose to pay by credit card, which usually means you do not have to register a PayPal account. Every country however has their own regulations by which PayPal is forced to follow, so this may differ slightly.

PayPal payment screen in Japanese (日本語のペイパル支払い画面)

PayPal payment screen