You probably forgot the manga introduced the other schools a long time ago since that was chapter 201. Definitely not out of nowhere.
I think Leiji and the other of the three grandsons of the Great 3 were introduced even long before that.
I'd be interested in the exact reasons people are icky about the potential relationships. People I know are massive fans of Flowery Path of Evil and at least the age gap there is much bigger so... Surely it can't be that, right?
Here's a taste:
Someone will need to drag me back to this story when that arc is over. At least the novel translations were long past that point when I found it.
And this is where Avril and Bertia differ. Avril pretends that she calls male companions as a matter of course. Bertia would never dare and would protest at the idea.
It's sad that some people have to keep making the "point" of saying this series is better without giving credit where it's due. The original and this version are both good for different reasons, appreciate them both even if it's just lip service.