Thanks to Tayakanagi's efforts, Izumiko has finally lost her rag at his plotting and scheming... and trust me, you don't want to deal with Izumiko when she's angry.
As a result, the school festival is thrown into disarray as Izumiko's temper causes all sorts of strange results, not least blowing out all of the electrical devices in the area. Oh, and turning Tayakanagi into a dog, which is probably the best result possible. The trouble is, the loss of phones and other devices makes actually finding where Izumiko is decidedly more difficult - then again, when you're on another plane entirely I suppose no amount of technology will help you.
It's up to Sagara to navigate these plans in the search for Izumiko - a task which is easier said than done, and as it emerges that Masumi is the real mastermind taking advantage of what's going on it also becomes clear that he's set up some tricky to navigate traps as he seeks to use his infatuation with Izumiko to stay with him instead. Ultimately, it's up to Izumiko to decide between Masumi's advances and her loyalty to Miyuki - no prizes for guessing which option she chooses, spurning Masumi's attention and the possibility of an easy life (or afterlife, I suppose) in favour of returning to the status quo.
Although it delivered a few sweet moments towards its climax, this final episode of Red Data Girl suffered from the same issue as much of the series as a whole - it felt like a show that was throwing things into the midst of the story with no real effort to explain or integrate them properly, and the result was inevitably a messy one that too often lacked coherence and focus despite having some good ideas and interesting characters to its name. It's this sense of disappointment that is perhaps what's made the series so frustrating - it isn't a terrible show in relative terms, but compared to its potential and blessed with some really nice visuals it could, and should, have been so much more rather than squandering all of its promise in such a dull and stilted way.