I think compulsory education in Japan is only up to middle school. High school is technically optional, but nearly everyone goes.
... You're spot on with the "manipulative behaviour" though.
It gets even better*, though, because the seasonal theme of the girls' names is paired with their love-interests'.
Koharu --> Sakuragi (cherry blossoms, big part of the Japanese spring experience)
Manatsu --> Matsurida (festival, which are held in summer)
Akira --> Tsukimi (moon, because the...
Don't do it Higashitani!
She literally just told you she treats everyone the same way. Her being nice and giving some advice is in no way an invitation for you to start pursuing her.
Oh, never mind, I'll just brace myself for when she rips out his little heart and stomps on it ... while still...
Never mind the speed, what about the height difference? He's about a foot taller than her, that crash should have been chin to forehead, not mouth to mouth. (Unless she jumped at the last moment, the sly little tart! :p )
It's probably a Buddhist/Shinto/Japanese cultural thing. Like how every member of a family has their own personal place setting (cup, bowl, chopsticks, etc.) which no one else is ever allowed to use, even after they've been washed.
You realise she's only figuratively a witch, right? She can't make a working voodoo-doll out of a hankie.
Oh, you meant her usual (non-supernatural) backstabbyness! Gotcha.
So unless there's a huge twist that hasn't been revealed yet, Kusunoki "nerded" herself on purpose in middle school?
That's actually got me more curious about the reason she decided to go back to her good looks in high-school.
If it had been simply bullying that caused her to put up that shell...
... cutting open a tauntaun for warmth on the ice-planet Hoth?
...
... on a plane? (cause, y'know, "snakes")
...
I really wanted a third one, because that's what comedic structure mandates, but it's kinda late and I can't be bothered. Also can't think of anything funny enough.
So on another...
Couldn't they fix that anti-magic problem in the engines pretty easily by regularly switching out the magic stones?
If they change to a new magic stone every week or so, the engine doesn't get a chance to attune to one stone's magic. So keep around half a dozen in rotation, adding in new stones...