Haha! That was some major plot-twist at the end of the episode! I’m not going to say what it is, though. I’ll leave that up to the next and final episode of this series. There’s just so much potential for it!
In any case, Mayumi turned out to be a small character in the end, whose purpose was to show Yasako where she had to go to find the other side. Mayumi just still hates Yasako, because Yasako basically did nothing to stop rumours about her and Michiko-san from spreading, while she had enough chances to do so. It’s like Mayumi said, Yasako tries to be nice to everyone, but when it really matters, she won’t do anything. That’s why Mayumi felt betrayed, and their fight began.
The reason Haraken was on the move in the previous episode was not because he still longed for Kanna. Instead, he somehow found out that Yasako was trying to get to the other side, and wanted to stop her. Tamako catches him easily enough, though they both end up collaborating in trying to get Yasako back. They’re too late, though, and end up sending a Sacchi to the other side. This Sacchi has a few modifications, though: it can fly!
(Thank god for wao’s summaries) And we finally know why Nekome does what he does: his case is quite similar to that of Takano’s in Higurashi: his father was a researcher as well, and when he finally discovered something major (I think he was the one who originally developed the Imago-function), this was taken away from him by Megamas. So he teamed up with Michiko-san to cause some kind of major scandal for Megamass, by making Michiko cause every kid with Imago to faint… so I guess that that means that the real reason why he allowed Isako to try and get her body back was for Michiko to take over Isako’s body. But still, did he have to go for such a complex way? Couldn’t he just have lured people inside the keyholes and make the v2.0s destroy them? That would have caused a scandal for Megamass as well, wouldn’t it?
I also wonder… where did Michiko originally come from? Did she just appear out of nowhere, or is she like the humanoid illegals, who in the end turned out to be products of Yasako’s grandfather that went out of control? Was she originally created by Yasako’s grandfather, but did something entirely different from what he had in mind? In this episode, she looked awfully human-like, apart from her eyes, perhaps.