Regarding kplug...
This is what worked for me, after spending a few days working it out. I worked close to Dunkler Messias's steam guide, but not precisely.
For example, I did not install BepInEX, IPALoader, KKABMX and KKAPI manually. I let HF Patch and the koikatsu updater to do all that for me. I TRIED installing those manually previously, but ended up totally messing up the game, forcing me to have to re-download the game
Also I don't have Koikatsu Party, but the JP modded version, Koikatsu Repack RX7. Koikatsu Party might have issues or just not work with the newest versions of the mods, but I dunno, I don't have KP, or have any need to try this thru Koikatsu Party. Just a forewarning.
1) Download Koikatsu RX7 NOT RX8, then backup RX7 in case anything goes wrong.
2) Download and install HF Patch, then install Uncensor. I also checked the backward compatability with older mods.
3) Install any additional mods through the InitSetting.exe (click Update on the window, another window will pop up, prompting you with some content you can download)
4) Install kplug.
I only installed kplug.dll, kplug Data, and remove mods with compatability issues. I DID NOT install the kplug uncensor. I figured out that kplug uncensor is modding the male and female models. kplug Data installs the animations separate from kplug uncensor. The uncensor downloaded from the Updater WILL WORK with the kplug animations, leaving kplug's uncensor optional. As stated from Dunkler's guide, you are left with cosmetic options for the models with the updater's uncensor, where as kplug's has some very minor custom animations and the skin overlay overlapping the m's g's. Just BE CAUTIOUS when you pull up the Updater again, as it will try to download the missing Uncensor files overridden by kplug's uncensor.
Hope this helps