Essentially, they use all public content on fire-use and don't claim authorship of it. That's the whole point of hentai-joi videos. Otherwise, no one would ever see such videos. You're essentially paying to read a beautifully designed story.Because they were DMCA striking it despite non of the animations and pictures in the video being theirs. Hell you can see patreon watermarks on some of them. I just find that wild they can claim it's theirs. Only thing I can see is MAYBE the voices. Even then they just hire VA's off reddit, So still technically not theirs.
TLDR they were copyright striking it despite nothing being their own original work and I think them putting THAT much effort into stopping some small leaks is asinine. (Some of the uploads lasted only a couple of minutes. That's petty to me.)
You'd probably not be interested in just looking at photo/video compilations that are in no way related to each other.