Started reading because the title reminded me of Roadside Picnic and... this is just an awkward knock-off.
There are certainly some fairly obvious similarities to Roadside Picnic (which I recommend reading, by the way) - and one story point (the bolt tossing) that's lifted so directly I'm going to assume it's a deliberate homage - but overall I think this manga is going in quite a different direction, given all the emphasis on Japanese ghost stories and urban myths, and the questions about the protagonists' differing perceptions of reality.
On which topic, here's an interesting tidbit: When our heroines are in between worlds, the writing on the signs goes all weird. That may look like Japanese to the uninitiated, but in fact all of those characters are just... wrong. A translation note to that effect wouldn't go amiss, actually.
Or maybe something like this:
Though that's not an exact equivalent, just a quick-n-dirty attempt at creating a similar effect (for English speakers) by mixing a bunch of pre-existing symbols from various alphabets. Doing it properly would be quite a task. And now that I think about it, you'd have to change all the real Japanese signs into English too, for consistency. Oh, well, it seemed like a good idea when I stayed up late last night to make it...