I think this is more likely, because I have a better moment when I think Maya was killed. Makoto's "A Matter of Time".
Maya is in the event earlier, Makoto is trying to get her to the RAS party. Ami shows up, scary red light, Maya is convinced to leave with her. Then the narrator brings up the colors, talking about how they are misdirection, a trick of perception, then they talk about Makoto and Yumi on the beach, the narrator starts crashing out about this, then there's a static jump where this screenshot is from, with dialogue written in a cheesy foreshadowing way.
Before there's a lot of static white flash and color flashing off as the narrator is cut off, figuratively and I think literally too. The narrator dialogue stops there and its just dialogue between Yumi and Makoto.
We've long talked about how characters have been narrators, and I think this was a tip of the hat to how Maya definitely was one of them.
As for why Nao-chan stops him. Nao-chan specifically isn't shown to talk in a pretentious all knowing way, she's quite down to earth when she has the notepad and tries to help in simple ways. I think she saw he was served a part of Maya, and she was trying to get him to break the perception trick being played on him to no success. Once the meal is done there's no need for her to struggle anymore, she's just frowning and the people posessing the other girls are laughing and insulting Nao, comparing her to Sensei.
I think it's doubly true if you look at the end of the event where they get their minds back. Tsuneyo recognises the scent of what's on him. You've already theorized that you think Tsuneyo's dad is dead, and his corpse is in Tojo Ramen and there's a smell to it. With the time shenanigans going on / Sel not thinking about everything 100% of the time, I doubt there's any thoughts to decomposition but maybe she recognises the smell of a dead body that Akira just bathed himself in.
"Matter of Time": I'm going to have to assert this without proof for now, but I'm almost certain the Maya in this event (the one who goes off alone with Ami) is Maya2, not the one who dies. (Doesn't mean you're wrong about the narrator)
Cannibalism: In "Cities in Gifu" Nao is unbothered when Sensei shows the head and says it's some noodles that he intends to eat. I think it's unlikely she would be so agitated on the first occasion and then care not even a little bit about whether he continues to eat more.
(Unless it's already too late. Now that Sensei has had his first taste of human flesh, he'll do anything to experience it again. The rest of the game is just him hunting down the girls like animals... But he's still hungry. He will always be hungry.)
Smell: This one is ambiguous. As you say, Tojo Ramen smelling like death is a recurring plot point. But in the event immediately prior to this one, Nao (through Kaori) says that Tsuneyo's home smells like pork broth. So a completely innocent explanation is possible. Arguably, though, neither one makes much sense - no actual ramen was consumed, and a fresh body isn't going to smell anything like a rotting corpse.
Do you have more theories like that? As a non-english person I may not noticed a lot of hidden things through the game and this makes read this update again before the 0.53 will be released. If you have can you send it to me all? I might start the game from the beggining again. And thank you for this.
I post something like this pretty often - I'd guess more than twenty times in the past year. I don't have a list saved, but it shouldn't be too hard to find them if you search my posts. I don't know if that's the best way to catch up with theories, though, I'm not the only one who shares them.
