Ah, I could just about write a book on this, my short answer is "don't bother".
That said, just Google "man arrested for decensoring videos in japan" so it can / has been done. But we are not talking about one thing here.
- In the past, there were specific censoring techniques used that were "more easy" to remove, this has varying degrees of success, and generally speaking you aren't going to do much better than some of the "decensored" stuff you see. You are far better off looking for some of the "uncensored leaked" stuff that was stolen from some studios (maliciously?, deliberately?, accidentally?, you be the judge) so it is before the censoring is applied... but that likely won't get you something specific like this.
- Contrary to popular belief, even though in Japan it is illegal to have uncensored content, the main reason it stays censored is so that the Yakuza can make money selling uncensored stuff ;-) I discovered this through first-hand experience talking with some people in Kabukicho (red light district in Shinjuku Tokyo), where it is sold pretty much only to Japanese salarymen.
- The "AI decensoring" is just re-drawing the naughty bits to approximate an uncensored result, YMMV, most of what I have seen is marginal at best, and it can take allot of effort for mediocre results. It's possible this will get really good someday though.
In my previous post, I got those uncensored pictures by downloading files based on some sitemap xml files someone obtained somehow (still would like to know who go those and how they did it). The ppl who run Onsen-phto.com obviously just upload all the raw photos to their server, edit them in place as needed, and only expose what they need to the website. But the index has "everything", including many of the photos prior to censoring, so there you have it. Unfortunately, all the videos I have (and I have allot) are censored like the one's you have here (you can see uncensored pictures of that girl in the download, but not video), my guess is that all the uncensored videos are on another computer that has the software for censoring those, and they only copy the censored result to the webserver.
I have not shared my videos because I got them from someone else awhile back, I am trying to reach them to see if they would be OK with me sharing them. Even though they are censored, the censoring is very light --- only if you see "bare lips" will they censor it, if the girl has thick enough pubes they won't, but the shaved girls always will. But, all things considered, I think this makes these videos mostly worthwhile (if this type of content is your bag), far less excessive censoring than your typical JAV. I have only seen very few uncensored videos / slips if at all of these. You can find some stuff by hunting down the individual girls and following them --- many have some partially or fully uncensored stuff on Fantia and other platforms they are on, or you can find they were formerly JAV stars and there are uncensored copies of some of the videos they were in. I mean seriously, look at some of the girls in my downloads, that many big tits can only be because they hired a bunch of JAV or related performers. Personally, I prefer the more natural girl-next-door types, someone you could imagine actually meeting.
Lastly, I have been following the news in Japan about some of the people who are lobbying to change the law about censorship completely. Fingers crossed but it could be awhile.
-jcl