For the end of the chapter, I wonder if chapter 5.5 was foreshadowing this. "Let's go to a hotel together right now and cause a huge scandal!" It's possible someone saw them enter the hotel or might see them leave it.
And next chapter could be Naoi's backstory where she tries to really get Kurumi to understand why selfless sacrifice can backfire on the person doing it. Though to be fair, Kurumi's internal monologue also showed how much anger she's been storing up over various things, including not feeling more rewarded for helping Naoi. I wonder if we get a flashback if we might finally learn Naoi's full name.
Naoi's dad is horrible. He outright seems to hate Naoi, including wishing her to be unhappy. And seeming to hold a very negative view of her as a person. Him not being afraid of the police implies that he's a person who's so hopeless that he has nothing left to lose, which is a potentially very dangerous person.
As for Kokoro, she's feeling bad, but at the same time is also missing the point. She still doesn't realize/accept that the Kurumi she knew was a facade. And she seems to still hold out hope of turning Kurumi back into that person. Though the cracking image of Kurumi's portrait seemed to indicate that Kokoro's mental image of Kurumi has begun the process of shattering. And she keeps replaying Kurumi's actions in chapter 10 in her head, which is driving her nuts. Her text messages indicate that she's growing increasingly desperate as she assumes that Kurumi's continuing to ignore her texts, not realizing that Kurumi threw away her cell phone.
I don't think Kokoko's mom is being very helpful. She might assume Kokoro is being overly dramatic, but at the same time doesn't seem to be trying to get to the root of the actual problem. Akane being there is the one hope Kokoro might have of not worsening. Who knows? Maybe Akane will catch the glass Kokoro knocked off the table instead of it shattering like readers might expect it to.
Only 2 chapters left in this volume, so not sure how it can reach a good stopping point with so much currently going on. Isanuma's downfall seems to be approaching though, as she still had a cameo this chapter along with her name getting brought up again. Can't wait to see what happens next.