It's interesting to see the main couple in a yuri manga overtake the side couple for once and then give the side couple the push they need to catch up. I feel like usually the side couples are the ones who push the main couple to their resolution, but it was the other way around here (although, Chika and Sakiko are more like a secondary main couple than a side couple with how much story focus they've gotten).
Anyway, I just binged this entire thing in one go and it's already 6am. It's incredibly good.