I'm expecting a new character or new criminal/villain now going after Sayuri (the childhood friend). The eyes of Sayuri's attacker doesn't look anything like Ayame's slit eyes when she is threatening someone. Given our current understanding (or best hypothesis), Ayame is definitely a supernatural and probably a yokai of some kind. And all of her supposed victims thus far took out their own eyes and arms. Ayame wouldn't need to torture Sayuri like this with blade/knife cuts (unless Ayame is doing this personally and physically without resorting to supernatural powers).
We should take note that Ayame in chapter 1, page 50 found and held on to Ota kun's "Omamori" amulet (for reference on what it is:
https://en.wikipedia.org/wiki/Omamori). I'd also pay attention to the knot pattern on Ayame's... neck band; which seems to match the Omamori's knot pattern pattern. It is entirely possible that Ayame is actually a "ward" and her elimination of the bully and Ota kun's dad granted Ota kun the immediate physical protection he needed. Looking back at chapter 1 page 4, bully literally said he'd stop once Ota kun is dead; chapter 1 page 22, even his dad threatened to kill him after beating the shit outta him.
Regardless of our hypothesis, the most important parts are that we haven't seen Ayame carry out the actual attacks, it's always been a time skip (except for the bully). Daddy drove the truck after he saw a figure and the bully did it to himself after getting spooked by Ayame. That detective is basically bullshi**ing himself and everyone around him with make-belief circumstantial hypothesis. I'd like to see a judge and jury actually try to take his words and convict someone without physical evidence or money trail (no evidence and conviction on circumstantial motives is basically a f***ing kangaroo court skit).
I also don't think Ayame is out to kill Sayuri, at least not at the moment based on her reaction to Ayame backing off on page 26. And Ayame actually not falling despair like the bully when Ayame looked her way; because Sayuri isn't threatening Ota kun. The more likely possibility is that Ayame knew about Sayuri's fate/fortune - but lightly laughing it off... is unnerving.