User blog comment:V3-CHAN/MAYUs BROKEN!!!!!!/@comment-25352448-20150101215015/@comment-32500188-20150102151909

^^This. Because chances are, if you're not able to get the demo installations working for you, you could very well also run into issues with the real thing if it turns out you're missing something that could possibly be preventing them from working properly. Just a thought... you wouldn't want to spend the money only to find out you wouldn't be able to use those, either, in that case. :-(

It'd probably help a lot if you could let us know a little bit more about what exactly happens when you try to install the demos, just to see if something is being glanced over unknowingly. Does it just do nothing after you double-click the setup.exe file? Are there any type of error boxes that pop up when you try to start the installation process or during it? Also, are you running the installer in English if the option pops up asking you which language to use? That might help you figure out what's going on if you do have any error pop-ups. (It's that very first box which shows up when the installer begins that should have two choices available: 日本語 = Japanese　英語 = English.)