Chapter 112: Interesting conundrum: ditch high school girl because aspirations don’t match or change majors to stay with “the Only One”? In this manga—they’ll stay together. IRL, thanks for the memories… moving on.
Edit: Blastaar’s comment was funny on a couple levels.
Except she'd do the same thing whether she stays or goes to Tokyo. She's gonna learn patisserie either way, it's just that before she assumed she'd stay at home since the kinda school she'll go to is already closely available so there was no need to think about moving until now.
Well, yeah, the romance-manga trope is that each person in a couple has to decide where they're going after high school, and the "romantic" choice is to be together.
I get the impression, though, that in Japan Tokyo is the magnet for aspiring young people in a way that isn't necessarily the case in the US or in Europe (and I definitely get that impression about Seoul in Korea). As Nanoha points outs, she has a handful of school choices in her region, but exponentially more potential schools in Tokyo.
In other words, for people from the provinces, the choice is between staying near home and getting an OK education/professional preparation or going to Tokyo for the big(ger) time start in life. But in the US that "bigger time" might be New York, but it might also be Chicago, or LA, or any number of other places depending on an individual's ambitions.