It seems like Kudou actually assumed that Naoi wrecked the arch, which makes sense given the text she sent Naoi right before it happened. This is probably what she told Kurumi off panel, which started to re-seed Kurumi's doubts. This chapter really highlights how much Kudou doesn't understand Naoi at all. Even thinking that Naoi isn't experiencing any suffering in all of this. Well, seems like she's about to get a wake up call, though I doubt she'll change so easily. Plus, she's likely furious about Kurumi's confession and if Naoi breaks out of her downward spiral as a result.
As for Isanuma, she must really be shocked. Naoi being cleared means she has to suspect that Mine is the one that wrecked the arch. And now she's seen what a scumbag their teacher actually is. I have to wonder what will happen when the story goes back to the school. I suspect the teacher will behave like every other adult so far does when faced with a problem, which is to say he'll run away and leave Isanuma to deal with the fallout alone. After all, he has no way of knowing that Kurumi was likely bluffing about having a recording, due to her missing cell phone. Remember she planned to go home and call Naoi in chapter 23, meaning it still hasn't been replaced yet. If Naoi comes back to school after being cleared, then all of the class will likely see it as proof of the teacher covering for Isanuma, making her school life even worse. I doubt Isanuma will stop blaming Kurumi for her problems at this point either, especially since she'll likely view Kurumi as the reason why the teacher acted out like he did and then bailed on her. If nothing else, it feels like Isanuma's being set up to be Kudou's pawn. Having Isanuma become so isolated is the perfect way to make that happen.
As for Naoi and Kurumi, it's great that Kurumi finally acknowledged/realized her feelings and was able to voice them, which is likely part of what the chapter title is referring to. Though based on what was shown of Kurumi's thoughts, I think her actual first conscious realization was in chapter 23. Now, to see how Naoi reacts. I think it will help snap Naoi out of her recent behavior to know that someone sincerely cares about her and won't just abandon her when they think she's being inconvenient to them, but with everything going on with Naoi's life right now, she might not accept Kurumi's confession immediately, but we'll see what happens in November, since the series is on break next month.
Kudou going after Isanuma is an interesting take; would using Isanuma help her to continue targeting Naoi in some fashion? I suppose if she can convince Isanuma that Kurumi
is "responsible" for the sensei bailing on her (I cannot
wait for him to eventually be outed and fired/arrested, btw), Kudou could then point her at Kurumi like some sort of aggressive & tortured attack dog, thus distracting her enough for Kudou to make additional moves on Naoi.
I think
that would depend on how Naoi responds to Kurumi's declaration, though. It is definitely out of left field, but I also think Naoi is fully in her own head about how worthless/hated she is, at present - so even if she has feelings/affection/love (of any kind) for Kurumi, I can't imagine this moment will simply "shock" her out of her ongoing tailspin.
It very much depends on Kurumi's resolve to hold fast to her confession through whatever fallout ensues, I think. In terms of the setup, Kudou's going to explode in some capacity; she already had a "what the fuck" moment when Kurumi kept pressing Naoi in this chapter, right at Kurumi's "why do you look like you're suffering? Your face is in pain, just talk to me" bit.
Kudou tried to recover by diminishing Naoi to "an inflictor" for want of a better word, but Kurumi broke through that again, immediately - so she seems to have the capacity to keep pressing Naoi to confront and look at her, which
could see this scene resolve with Naoi walking away from Kudou's influence, if only for the moment.
Depends on if Kudou tries to get physical, herself - if she attacks either of them, Kurumi would likely defend Naoi, and if Naoi defends Kurumi, Kudou's on predilication of wanting abuse from Naoi might actually cause her to falter and flee. Don't know if that's how it'll play out for sure in November, but the line is there, I think, based on who each person is & their mannerisms, and the setup / energy of the moment.
I do think that any acceptance of the confession on Naoi's part will be
incredibly tenuous though, and will require constant reinforcement on Kurumi's part, for likely a long period of time - which, with Kudou, Isanuma, Mine, the sensei, and Kokoro fully involved alongside the ongoing scandals of vandalism in the classroom (oh, and Naoi's dad), I very much don't seem them being "out of the woods" anytime soon - with much backsliding along the way.