Unfortunately, it's got the characters from another franchise in it. So you really need to have read the VNs to "get" the game, and there may be licensing issues and bluh. I know that 07th Expansion franchises are popular with some people, but this one probably has a few too many issues for us to seriously consider (unless you want us to go all Street Combat on the game... no, didn't think so ).
No characters from other franchises in it, just the one, whose copyright is held by the same group. The music might be all over the place though.
Also 07th expansion allow all derivative work, this includes fan translation patches. They went far enough to block the English licensor for Higurashi from C&Ding the fan translation for it. It's going to get fan patched if that's technicaly possible, and probably fairly quickly.
The VNs are available in English fairly readily, especialy if you live in USA, UK, Australia, Spain, Italy, France, or Norway
. If not they're distroed through normal shops not just doujin ones, so they're easy to buy anyway.
This is up for preorder at amiami