We girls normally are not like that, normally is only a few... but still in almost all mangas types except Shounen, som Yuri and Seinen women are seeing like that... specially in Yaoi and Shougo... but you will see that almost all mangas (not all) that show schoolgirls like that are mangas done by women...
A friend from Japan told me that the only real thing is how they are trying to find a future husband (less now than before) and is because in their culture if they don't marry young people will say they failed in their life... is easier for a divorced woman or a widow to marry in certain age that a single woman...
Eh I go to an all girls boarding school ahem*nunnery*ahem and basically most of us act like that. Either that or we’re emo ╮(￣▽￣)╭. I belong to the latter tbh
Not as bad as some, but this still makes girls look like whiny, thirsty bitches who don't care about anything but getting/marrying a handsome, rich guy and think they can get away with anything.
Seriously, seeing this was set in an all-girls school, the girls would be used to NOT being boy-crazy and flirty and all that. With the setting so full of girls, I felt this had promise to contain at least a few fleshed-out, strong female supporting characters! Not all girls are hunting for their future husband that will be the bread-winner as they stay home!