It just dawned on me that Rina, Nanase, and Mai all have some sort of behavioral issues because of trauma related to their parents, which is not the case for Sayuri and Nozomi. I feel like the show hasn't explored these two as much as it should, and going by the opening, there's more to them than what we have seen so far. I wonder if, by the end, they will also have something like the other three.