If this series started with Sayaka and Touko meeting for the first time, and went though all their school years first in like say 60 chapters (30 per school year)... What would you think about Yuu then? Would your perspective shift or change regarding her and what role you would assume she should play? Would you be more comfortable thinking of her as that helpful nurse who gets her patient back on her feet, or a heroine who will get the girl in the end?
Well, sure, which is to say that there’s such a thing as narrative focus. It’s not as if these characters exist outside of the text we are given and thus have a ”real” role that readers are perceiving accurately or inaccurately.
I mean, the story could have started with Koyomi (or Maki) as an outside observer/narrator, watching and reporting on the interesting dynamic among two senpai and a first-year. Then it would be that story, told in an entirely different way.
Or it might have started with Mio’s funeral, and shown us in detail the entire process of “weak Touko’s” self-transformation, then cross-cut to a full delineation of Sayaka’s relationship with Dumper-senpai. But none of those stories actually exist.
What we do have is a very odd bent-genre “romance only if there’s no romance” romance, which, having stipulated up front that there can be no ultimate romantic resolution, proceeds to throw out all the genre signals of a romance.
No wonder we’re always a bit on edge. :)