That would be really cool actually..if Nina was indeed that girl from the manga and not just a character the author used again. Like, Nina was starring at those mangas and that's why she and her sister are so open on the girl on girl relationship, lol.
I hope we don't get a real incest though. I mean Yuzu and Mei are not really sisters, but an actual incest would ruin it (at least for me)
I wonder, if this manga ever gets an anime adaptation, how long it would be. But I think one chapter is too short to be one episode...unless they add some extra stuff in them, like exploring the side characters more, or showing how the girls spend their free time outside school/ going out. It would be cool :D Oh well maaybe one day...