BTW I’ve only read the first two volumes so please don’t put any spoilers thanks.
Actually, if I remember correctly, Shirai and Haitani’s university is in Tokyo (although I’m uncertain whether or not it’s actually Toudai), which is also where the prep school was (if you notice Keitaro and the rest of the Hinata crew are frequently shown commuting there by train), so I assume Shirai and Haitani live in Kanagawa, the coastal town on the western outskirts of Tokyo where the Hinata Sou is located.
After all, they’re often seen riding the trams which run through the Hinata townsite to the train station. Plus, how else would they get a job at the Kanagawa Neverland amusement park, if they didn’t live locally?
Incidentally, Keitaro didn’t change prep-schools when he moved, because it was the still same one which Naru was also attending, even before he moved to the Hinata Sou, so I doubt Naru would change it after she failed the exam (ironically enough, it’s also the same one Motoko ends up attending at the end of the manga and in Love Hina Again).
Still, it doesn’t really make that much difference in an ultra-urbanised country such as Japan anyway.
Now it’s all ruined, RUINED. *sob*