Hiyori is gonna play a role in kiyotaka's change
Why do I think hiyori could play an important role in kiyotaka's change?
Kiyo is expecting to change with this new feeling:
>And what kind of effect that emotion would have on myself, and on others. Would what came next be prosperity, or ruin? Or perhaps, something else entirely? I was, at that moment, living a very fulfilling—contented moment. For that, I had to be truly, deeply grateful.
^((The "and on others" part stands out to me. Kiyo isn't only curious about how these feelings will change himself, but also about how they'll affect the people around him, it's interesting to see how his feeling for hiyori have already affected charachter like ichinose. Whether that's intended or not, I think it's an interesting detail.))
another:
>That wasn't a sound signifying the end, but a beginning. Was I allowed to believe that? Would I come to know love as an ordinary high school student, and continue to grow from there? Will I be able to change?
This shows that his change hasn't been completed yet, it's only the beginning. I find interesting that in the same volume of the "Will I be able to change?", in the nanase and ichika conversation, nanase talks about trying to bring "a change" in kiyo's heart.
Then we have ichika saying in the same conversation:
>"I’m not really sure whether he’s interested in living a normal life, but I think he’d find returning to the White Room far more appealing."
The "normal life" she mentions is interesting because hiyori is the person with who kiyo experiences the most normal moment. They're interaction are simple and peaceful, whitout the manipulations and schemes that define most of his other relationship. That's why i think the change of heart and hiyori can be connected. I'm not saying hiyori is gonna change kiyo completely, but a part of his mindset.
What part of kiyotaka's mindset hiyori is gonna change? / How can hiyori exposes a contradiction in his mindset?
What i find interesting is that hashimoto and arisu don't point out that kiyo and hiyori are close. They specifically point out that kiyo treats hiyori differently.
Kiyo has always believed that everyone should be treated equally and is one of the foundations of kiyo's character. Since the very first volume he tried to understand equality and to treat others equally. But hiyori is the first person who naturally breaks that rule. He doesn't decide to trear her differently, he simply does. That's why I think she may change part of his mindset. Not because she forces him to, but because she makes him realize that treating everyone exactly the same isn't what a normal person does, that it can actually make it harder to form genuine bonds with others and enjoy it.
If that's the case, it could also be the first step towards the kind of change nanase is trying to start about.
This is the proof that he treat hiyori differently, even if the proof can be him calling her by the given name:
>"Then, what if that person were Shiina-shi...?" And then, Kaneda brought up Hiyori's name. She was, indeed, one of the most appropriate students to use as an example in that situation. I intended to reply immediately just as before, but the words caught in the back of my throat.
This part is just my personal hope for the story. He was viewed as heartless, that betrayed his class without a reason.. Him saving hiyori can let him have more close friend, like yoshida as we saw, horikita maybe for they're interaction in Y3V4 they can become best friend who care and cover each other, and i hope morishita too🙏