This is why this is my favorite yuri manga ever, the author knows what we want to see and delivers every time. I've been reading yuri for probably over a decade and it's honestly so refreshing to see a series like this that doesn't feel ashamed of itself like so many other yuri out there. It doesn't waste 10 volumes on the characters very slowly working up to getting together, it doesn't do any of the "omg but we're both girls, girls can't love girls!" shit, it doesn't bait with romance subplots that go nowhere or constantly introduce forced melodrama or be obsessed with purity or miraculously have a random disruption show up to distract the girls just before they're about to kiss, while at the same time not just being pure pornography for straight men that you feel dirty after reading and actually gives character to all the girls and spends time for plot and fluffiness. And since this manga has been such a success I've seen so many more manga that are actually proud of what they are and celebrate yuri openly without all the baggage the genre has had, we're in a yuri golden age and I think a large part of it is owed to Asumi, the yuri gigachad.
The author said fuck it, I know you want to see Nanao and Asumi get together, lets do it. And I love that. It would have been so easy not to but they put in the time to set up the moment and (hopefully) are going to actually pay it off which I hoped for but didn't expect. I'm still hoping for a harem ending because I love all the other girls too and I want to see the story continue since I think it's kind of dead if Asumi gets into a relationship, but I'd love to see Nanao also getting into brothels and Asumi having a degenerate friend to share her hobby with. That would be a really fun development