What is it that this shows about Japan that is actually all that unusual? Not much, I reckon.
The idea that Japan is mired in the past? You only have to look at the Tokyo skyline to realise this isn't really true, and have a brief look around the UK to see other places that are just as stymied by history. A history theme park? Isn't that what somewhere like Ironbridge is all about, only less involving and interesting? I've visited O-Edo Onsen* in O-Daiba and it offers something similar - a fun diversion that is well worth the games it plays with historical accuracy.
How about the assertion that these girls are "escaping the present" in their interest in the past? Well, surely an interest in the past as a displacement activity is an improvement on the broad disengagement with reality around one that obsessions with Strictly Come Dancing and X Factor engender?
I think the unmentioned aspect here is the cosplay that is alluded to in the final part of the clip, and we all know that if you want to have a laugh at Japan, cosplay is a safe trope for which one does not really need to work too hard. And as a final note, how likely is it that this is, as is so often the case, actually a very minor activity with a handful of exponents that is looked upon as much as a novelty by J-media, but which is presented to the world here as a mainstream development? Perhaps I'm cynical in trying to find stories to blog about.
* Wow, do you see on that link that it is open 11am to 9am? Not a misprint, it's open 22 hours, so you can head there overnight if you wish. Cool.