Even more vibes from Ai Kamiya (from Shikimori is not just a cutie) being a girl admired by everyone, with a lot of theoretical friends... but without real friends, without people in who she can trust on, because her own communication problems.
These communication problems are other inheritance from Kazusa Touma (White Album 2), of the same author.
Only Izumi and Nekozaki, I mean, Haruki and Setsuna, I mean, Yuu and Hikari, were able to break her mask and see the real Ayami under the cool girl facade. Only them reached to connect really with her and break her walls.
And yes, this imply Yuu always was her fated couple, like Izumi was for Kamiya AND Shikimori. They always were predestined to be the first love of the other one, the abussive step-father of Ayami only fastered the process.