I never really like this manga, it is too sensitive for me... It makes me feel tiring and sad, until the ending of course, by then I just breath out in relief and think the mc is a super lucky girl. The supposed unrequited aspect is definitely the reason why this story feels so depressing to me.
Still, as I was rereading it, I realized how this story portraited so well the image of an "unreachable" crush, and the feeling of falling for them. Even though Chizuru constantly praised Kanae, there were moments when she was intimidated by Kanae. She put Kanae on such a high pedestal that the idea of being loved back seemed impossible. She chose the most passive way to express her feelings, and only for herself to see. Because of this, despite being the embodiment of beauty in Chizuru's mind, Kanae still appeared to be stone cold (and so so far away) at the same time, both to Chizuru and the reader. When the feeling turned out to be mutual, then you saw Kanae expressed more emotions.
Maybe I read into this too much, but I just like the idea of breaking someone's inhuman (good or bad) image in one's mind, revealing that someone to be just a normal person, and not so unreachable as you first thought.
Anw, that's another way to read this manga. I still don't really like it, but it is a fine read.
P.s: Just bring your crush under the sunset with you, then your feeling will be returned.