http://www.hongfire.com/forum/showthread.php?t=84564
Here is what you do:
Download the megaupload link first. After it is done: download the link below, which is the update. That link will direct you to a Japanese page. The most recent update is 1.06, so click the link at the very top.
After that, put the update file into the same folder as the game file, then extract it with WinRAR or WinZip.
Once you do, open the update and it will apply it to the game. Then just click on the main application file to launch the game.
I haent gone online with it. I am being told to download a program called Hamachi which allows me to play others online. The game can naturally go online, but since it is an .exe file, there were a few restrictions. It isnt anything technical, it just requires the right stuff to do it. No hacks or anything, so it chould be safe on your pc.