I suggest you go to IWARA and search using the tag (koikatsu). You will find a ton of works with exactly the same animations, only the characters are different. As for the authors you recommended, take a closer look—do you notice any differences in the animations compared to what I mentioned? After all, among the authors using (koikatsu), only 1 or 2 out of 100 actually create their own animations and scenes. The rest just copy and paste, without any original creation at all, simply because they are lazy.