Okay, major spoilers for Wonder Egg Priority. Consider yourself warned:
First of all, it turns out that Ai's friend, the one who committed suicide and got the plot kicked off in the first place? She actually didn't commit suicide. See, she had accused a teacher of doing "something" inappropriate, but it was actually a lie and she had a history of making false accusations. And she didn't commit suicide, either- she'd been on the roof acting like she was going to commit suicide as part of her false accusation but what happened was that she'd stumbled and fallen off the roof by accident.
Simultaneously, we learn that the two mannequin guys are actually human scientists who had in their spare time created an AI that looked like a teenage girl (creepy much?). This AI got jealous and possessive and murdered the wife of one of the scientists, so they tried to disconnect her but she ended up somehow being the one who was behind all the teen girls committing suicide because of reasons that are sexist BS. And then she also creates other AIs that look like teenage girls with insects for heads.
And the final episode was delayed with a promise that it would be a full hour finale, but it turned out to be 25 minutes of recap (after episode 8 was already a recap) with only 20 minutes of new content. Nieru turns out to be another AI who winds up staying in the dream world with the villain, and there's more stuff that wouldn't make much sense if you haven't seen more of the series.
