It was made by a crowd called Sakura. Apt title. As for where it comes from, try this:
www88.sakura.ne.jp, and if that doesn't work, leave out the 88.
There's also an internal link to the site on the games' main screen. I'm not sure, but I think they have a few more like this.
I have a walkthrough somewhere if you want it, but I'll have to come back another time to give it to you.