I finished Kosame's route. It was unexpectedly shorter than the others, and a few key details piqued my interest here and there, but it ultimately felt like a weaker route since you unlock this after Komomo's, and by then you would've already known the big reveal so the writers pretty much knew there wasn't much else they could do with Kosame after that.
The dynamic between her and You was so-so for me, but it was elevated a bit if only because of the supernatural circumstances regarding Kosame's existence. Asuho's and Komomo's routes are still undeniably stronger than Kosame's for me.
Now then, off to Aoi. I like her VA since I read Fureraba before, and I guess I just missed hearing Himari's voice, even if she's a little more sadistic here than before.