I think people are ascribing too much agency to Maya in her relationship with Sensei. She was seven years old, I'm going to need a whole mound of compelling direct evidence before I believe that she was the instigator or driver of a sexual relationship with an adult, and even then the first assumption should be that she was groomed into it. I think, if anything, the scarf story even points against it. It was Sensei that fingered her, all she did was confess her love (again, the love of a seven-year-old).
Which one? Noriko insists someone (assumed to be Maya) did something to/with Akira in the Old District after he ghosted her, and she saw him from the bus. One theory is that Maya made out with him in public or something, in an effort to make him leave the old district for good - but that's a very steep shot in the dark at this point (this happens during her first conversation with Akira about the past, in which he starts to shut down).
The other time Noriko mentions something related to this is directly to Maya, but that's more about the fact that she had sex with him while being a kid, putting him on a road of no return, and that she knows that Maya also knows she ruined him by doing it. Which is totally true. There'd be no person not sympathetic to Akira if not for the Maya situation - up until that point he was 100% just a victim of a horrible person, and there is a strong hint that this act was in part pragmatism from Maya's end to cut him off from everyone else as well (New Maya jokes about calling the police if he doesn't have sex with her, and at some point this might have been actual blackmail - if he didn't leave Noriko/Niki/the Old District).
I don't have an explanation for Noriko's story, but I'm not convinced that it's Maya that she saw. According to the pact they made as kids, Maya can't go to the old district, yet both of them seem to agree that it was Noriko who broke the pact in the present day. If Noriko saw Maya in the old district, surely she would bring that up.
As a side note, I still don't understand what Noriko was supposed to get out of that pact. Even if she was a kid and didn't understand the implications, she must have agreed to it for a reason.
I don't think Maya kissing him in public makes much sense. It's not like the old and new districts are completely separate worlds. If he's at risk of being recognized and unmasked in the old district, that risk would still exist elsewhere in the city even if it's less.
New Maya mentioning the police came across to me as a sex kink thing, since Sensei gets off on how taboo his relationships are. I don't think there was any indication that it was an actual threat or that she had threatened it before.
Noriko does imply that Maya is the one who fucked Sensei up for good:
Mentioned it before:
But it does seem like within months of Sekai's death, Wizard Maya had Sensei wrapped around her finger, and Niki was out of the picture.
As this thread's resident Noriko hater, I feel obligated to push back on some of this. To start with, Noriko is not an objective source when it comes to Maya. Her feelings towards her are all kinds of confused, but they include jealousy and bearing a grudge over the past.
More importantly, there's a lot of stuff that Noriko doesn't know about. She doesn't know about Sensei's relationship with Sekai, which was probably a big impetus for why he had to leave the old district. She doesn't know anything about what happened between when he left and when she joined the class. She sees that he's even more broken now than she remembers, so she blames Maya for that, but up until whatever triggered the resets, it seems like he had actually improved significantly outside of having an underage girlfriend.
In context, what she actually blames Maya for is not fixing him, but she doesn't know that the resets made that impossible.
Maya isn't responsible for Sensei ghosting Niki, that happened immediately after the accident when he holed up in his house with Ami. After he started improving and leaving the house, he still chose to avoid her. Even Noriko doesn't blame Maya for him abandoning them the first time.
It's reasonable to argue that Sensei would have eventually let Niki back into his life if Maya didn't push him away, but there isn't any evidence that he was considering it. I think it's telling that Sensei never talked about the Nakayamas with Ami.
As far as I'm concerned, the only thing that Maya was guilty of was pushing Sensei to leave Noriko and the old district behind. Even then, she thinks she had a good reason for it, though I'm sure her selfishness and jealousy played a large part.
It's also worth pointing out that we still have no idea why Maya hates Noriko so much, and Noriko clearly doesn't know either since she thinks it's for loving Sensei, which she realizes makes no sense.
I can't see Maya Prime maintaining this hatred for thousands of years unless either: 1. Noriko has been showing up during resets (and Maya lied about it). or 2. Maya blames her for some aspect of Sensei's present condition.
Edit: Last possible reason is half tinfoil, but it could be that she hates Maya because they're both pursuing different goals reset wise. They're the top narrator guesses after Himawari, and her hatred could be a "present" hate, born during the resets, and for supernatural reasons - rather than the hate of the memory of a dead person looking over someone that wasn't even part of Akira's life when she was alive.
I'd actually argue that this is the only reason that we have direct evidence for. Sekai and Pareidolia view Sensei being broken as his true self, and they want him to return to that and become the Collector. Maya Prime was pushing him in the opposite direction, trying to get him to care about the girls. When Pareidolia talks about Maya grooming Sensei, he's referring to what she's done during the resets, not to their sexual relationship.
