This is the point where I will come to that strange presentation. As already told in the first category the story really is confusing and hard to understand. Personally I like difficult and artistic anime but this one surely overdid it in its strangeness. That is why watching Boogiepop is a bit frustrating until the last few episodes where the mysterious riddle is solved bit by bit - of course in a disjointed manner again. Important facts are only told once in the anime so you will have problems in understanding if you do not watch this show attentively.
On the other hand there is this really good directing style featuring some shocking scences mixed with individual drama.