I don't get to use this nearly as much as I'd like to.
IIRC he said he pulled Sekais body from the "twisted metal" in one of the events after the beach
Back in the 'Mysterious abundance of chickens', the Narrator says:
"You kneel down and remove strips of steel from her body."
It also mentions "The screech of tires", and "You saw it all. You see it all.", so it definitely seems to be alluding to the car accident and Sensei being there for it.
I'm caught wondering if Sekai actually cares about Akira, in "Worry Not, The Mason Jar" she seens genuinely worried about him.
Sekai has seemed to claim that Sensei is the one she loved most before Ami:
I think Sekai genuinely cares about Sensei. Just in a way that didn't stop her from traumatizing and using him.
Forming an idea of how the accident occurred remains ground for speculation. Even the the little tidbits of information we have are confusing to me. Let's see:
But alas:
Anyway, I find this important because wheter Sekai was in a car or the other would help to put some theories to sleep for good, and narrow down our speculations a bit, something that is really necessary at this point
I do think the yellow car is connected to Sekai, but I don't think we should take the "run over by a car" thing too seriously. That was Sensei during the first reset, in the 'Reset' main event, and he likely didn't know anything beyond there being a car accident that killed her parents, and on top of that, he was delirious.
Still, that could have been what happened and the other stuff is actually meant to be misleading. Of course, it could also mean that her parents ended up underneath their car in the wreck or something. I can't wait until the game clarifies on what happened. It's been years in the making.