A few of its functions are unavailable until you enter a lisence keycode. The keycode to enable the unavailable functions is provided when you pay for it.
The unavailable functions are the "Saving" and "Exporting" functions.
Except for these functions, you can use all functions without any limitations even before purchasing a keycode.
If you like Pepakura Designer and want to use these unavailable functions, please buy a keycode after you confirmed that Pepakura Designer runs on your PC without troubles.
Please access Pepakura Designer's official websitesite, http://www.tamasoft.co.jp/pepakura-en/ , and see the Buy Keycode page.