First would be the setting. As I mentioned, I'm in most part inspired by a Japanese light novel series, so I would most probably set the game in modern-day Japan, though if others would rather have it elsewhere, that's doable.

Second would be the theme of the RP. Now how the setting works is what's set in stone, what we can do with the game is very flexible. Teenagers stumbling into something dark and dangerous that should be left well alone? Or maybe Teenagers having Scooby Doo run-ins with the supernatural? A family moving into a haunted town? A team of "specialists" aiding the overrun town? The possibilities are quite numerous.