What is going on with Kanoko is an example of dialectical development.
Kanoko at the beginning of the story: I don't want reciprocity or intimacy from Hime-chan, as long as we have a very special platonic spiritual bond, I can't want more than that. That's the thesis.
Goeido: Your very special platonic spiritual bond means nothing if you don't want to fuck your Hime-chan. That's the antithesis.
Kanoko now (well, not really now, but she's definitely moving in that direction): I recognize the importance of the physical aspect of a relationship, but I also don't dismiss the primacy of emotional connection. That's the synthesis.
The only thing left for Kanoko is to realize that she already has a much stronger and deeper emotional connection with Sumika than she has with Hime in all the years since they have known each other.

Hmmm... Who's the main couple in Watayuri? It's so hard to tell...