Then again... >_>
Genre conventions are weird.
"No," "Stop it," "Don't!" are common tropes in japanese media though...they even say it when they are into it and are just shy about it, so it's hard for me to take it seriously in manga.
Well, fair enough. But personally, no matter how many times I see it in manga, yuri or otherwise, the idea that "No" means "Yes" still immediately breaks me out of the story.
I still wouldn't say it's that common. It's common in yaoi, because fujoshi sometimes have these weird rape fantasies, where they'll borrow the body from the uke.
I suppose it's not exactly the same as with yaoi, but it's still one person forcibly initiating sex without obtaining consent.
You could argue that it's just fiction and it doesn't have to be realistic, but on the other hand you have stories like this, where even without the age gap it's pretty fucked up and not pretending to be anything else.
Delinquents and aggressive girls in general are pretty rare in yuri.
No, they're pretty common.