I play on Windows 7, that I installed today on my MacBook Pro. I'm using Internet Explorer 8, and I had no ActiveX problems, I couldn't believe it ! You just have to be patient on the website, when it asks you to install something it can be long to react to your click.
The only stressing part was downloading the game and the patch, because it was veeery long (probably due to the Hotspotshield vpn), and it sometimes crashed while updating. So in this case, what you must do is deleting the file from your computer, with its directory (up to the patch folder in the case of the patch, the Play NC folder in the other case).
So it took me something like an hour to complete the update/patching.

Now that I can play, I'd like to know if there is somewhere on the net a tutorial that explain the japanese menus ? I found nothing else on google. I manage to understand the Katakana words in the game, but there are so many setting options, it's a bit confusing :)
Anyway, thanks for the translations in this article, it's very useful.

So good luck to those who can't play yet, I know it'll work !

>One would think if the juice is worth the squeeze.

Well I think it worth, is just for you think about that! At least you could play.

>I got HotSpot and it works perfectly but for some strange reason I can't log in the janryumon site anymore, the error for ActiveX pops all the time and I have it >.<

I don't know why but it's hard to intall the ActiveX.It taked me quite long to do it. This with a fresh install of Windows 7. Maybe it's a trick who I just passed up while I installed, but for sure theres anything who we miss so it make quite hard to start the install. The only thing I could say is try, try and try. Also If you have Windows XP or Vista with more than a year... It could be probably the pain in the ass called Internet Explorer. Greetings!

One would think if the juice is worth the squeeze.