For the record the false memory I referred to is any memory that conflicts with what Sensei remembers (or at least what players saw), regardless if it later on got corrected or rewritten or not. So Makoto's no longer existing suicide attempt is real, the may-or-may-not-existing 3rd reset sleepover is real, years of memories compressed into one single semester are all real; they just don't make sense, but they're real.
(but by my own logic this means Tsuneyo knowing Sensei's first day speech would be a false memory, something I am not too sure how to think of haha)
I see, yeah, I wouldn't really consider Sensei's memory all that reliable though, and perhaps he affects what we see happening instead of what actually happens, so even what we are shown isn't necessarily reliable.
Like this for example:
Still, Sensei's memories themselves are untrustworthy. Especially those involving the roof with others besides Maya. Take his meeting with Ayane for example:
There's no logical reason for her and him to have met at the top of the roof during the slumber party and right before the reset. Even though we saw it.
In other words, It's possible that Sensei's memories (and our own) are false as well. It's possible that Sensei, Sana, and Ayane all had their memories altered at different points. It's not like Sensei's memories are some exception to the rules. Not to mention, he seemed to be trippin before meeting up with Ayane:
So, the roof stuff could have never actually happened, and we, as well as Sensei, simply saw it that way.
Also "
Nothing is real". But, yeah I get what you're saying. Tsuneyo is definitely an outlier when it comes to this stuff.
Overall: I consider false memories any memory that seems to be edited. Albeit depending on the context, retconned and rewritten could fit better.
I read this in a much simpler way, that Sensei starts being weird about something happened so recently, and Sana merely confirmed that what Sensei thought to be a no longer existing sleepover still happened, with a tinge of "are you okay?" tone rather an uncertainty. I'd probably respond the same way if someone suddenly stares at me and has an out of nowhere existential crisis over a sleepover.
"Ended strangely" is indeed intriguing; unless she was just referring to Sensei leaving the sleepover in the middle of the night after getting a call, but I am open to the idea of her witnessing something when a reset takes place. As for her "remembering" something Sensei said only to the first 10 girls (well, 9 because Yumi wasn't there lol), I think this might be less about Tsuneyo but more about this new game+ mechanics that Kumon-mi uses that has an effect on her; if only we can ask Molly the same thing and see if she also remembers a speech that she wasn't there to attend.
I definitely get more of a "It's hard to recall, but it had to have happened as I remember certain parts of it" interpretation, from Sana. But to each their own.
Sensei leaving, wouldn't really matter due to the slumber party not ending just because he left. It definitely seemed to end before he returned though. Tsuneyo also seemed unfazed by girls going Tshaped and the rabbits and stuff later on:
So, her definition of "strangely" is likely significantly strange. Can't really think of what she could be referring to besides reset stuff, tbh. Molly's input would definitely be interesting though, but it's possible she'd have false memories as well.
I thought Sensei questioning Ayane was Sunday-Monday (aka about a day after the sleepover) and not Saturday-Sunday is solely based on her saying "...even if it's almost time for school" during a 3am exchange, so I quickly went back to a 3rd reset save to check on exactly what day it is.
Sensei went back home to sleep at the start of Word of the Day, which takes place after meeting with Ayane the first time on the roof on Saturday night, then it transitions to 3rd reset BS puzzle part of the event that takes place on Sunday. Then, what followed immediately after 3am exchange is (bad uncle route) As Light As Air on Monday.
Though what exact day it is probably bares little relevance, this is a very roundabout way to say that Sana can be at her dorm when Sensei checked on Ayane because the timepoint of that may-or-may-not-exist sleepover has already been in the past; Sana's presence there isn't a valid evidence to prove that the sleepover got rewritten into never happened (i.e., not a "Weren't you supposed to be in my house?" kind of encounter). The technically today to me is as literal as Sensei revising himself since it is not Sunday midnight but Monday early morning. Once again if only we can ask Molly again to see if she remembered anything about a sleepover lol.
But I do notice that Ayane said "And I can't really figure out why Sana would be here if there actually was one [sleepover]" a bit confusing though, a piece that doesn't fit well into what I proposed (so here you go my weak spot!). And I think there is still a possibility that the sleepover became "unhappened", but current findings aren't concrete enough to support it.
I'm pretty sure it's just Saturday night to Sunday morning. It's why Sensei asks what Ayane remembers from tonight and she replied she was with him:
Which is something that happened on Saturday night during the Slumber Party.
Ayane's reference to it being almost time for school was in reference to school being tomorrow, so going over to a Slumber Party today wouldn't make much sense. It's likely why Sensei notes he didn't realize it was Sunday after she says that:
Then that he'll be a real teacher tomorrow:
Before rephrasing it, since he's deciding to be one right now. It's also why he wanted to see if the Slumber party was still going:
Since they should still be there. Which wouldn't make sense if it was Monday morning.
I also think 'Light as Air' takes place about 3 hours after talking to Ayane, post reset, around 6 am:
and the references to screwing Ami before school was just roleplay.
As for the reset itself, after talking to Ayane it seems to start when Sensei gets home hence him saying "I'm home":
Then he breaks out of it "mad quick":
So, I don't think much time could have passed since he talked to Ayane. Maya hadn't even got to the roof yet apparently.
Overall: It's an overly confusing event chain that can be easily misinterpretated. But I think the whole thing actually took place within hours, between Saturday night to Sunday morning.