I don't get it though. Is she just constantly moving schools?

yeah, but the first school we see is the most important in the series. Shes an 'observer', until she meets the 1st school classmates. And then when she moves around, she speaks up and helps all of these different people in the school. I dunno, I found this manga really amusing

Oh yes I love it too. In the sequel they were a lot more straightforward about her moving schools all the time.