It works.
For future reference for anyone who finds this thread:
If you get errors about missing DLLs then the easiest solution is to compile it manually. Install Visual Studio tools and use a command like `cl.exe plt.cpp /std:c++latest` to generate the EXE.
Drag the plt files onto the exe. The PLT files must be in the same directory as the exe and must be renamed to contain no strange characters.
Of course, here you are: https://github.com/Anonym271/jkimouto-tools
It is no problem, I can try to give you a little introduction into this if you want (although I am by far not an expert myself). But I would suggest to do this via Discord (Anonym271#6243) or another chat messenger rather than here in the forums.
The PLT files of the game are encrypted for some reason and Arc Unpacker does not know this encryption. I found the decryption algorithm in the game and was able to rewrite it, but sadly I could not yet find out how the keys for the encryption are generated. I finally ended up just dumping the keys out of the game's memory and using it for my own program. You can download the program here.
It should be able to decrypt at least most of the PLT files of this specific game but I can't say if it will work for all since I only have this specific encryption key. Let me know if something doesn't work.
The ANM files are probably only there to tell the game how it should make an animation out of the individual frames, that's why they are so small.