Sorry I only speak english. It sounds like you have set the libraries set correctly, but the folders aren’t labeled correctly. Most likely Plex didn’t find those shows you mentioned because it “mis-matched” them. One of the big parts Plex uses to identify that a folder is “Log Horizon” is by the release year. So you should really go through your folders and rename the shows to include the (YEAR) after the name, like so: Log Horizon (2013). Failure to include it may cause plex to mis-identify the show, or even think it might be an entirely different show altogether. Afterwards, do the Plex dance on the specific files
From your screenshot of your folder structure, the only one I can see that you mentioned as having a problem is Demon Slayer. The others (Log Horizon, Tsukimichi Moonlit fantasy) must be Japanese shows further down in that list. So I can’t tell for sure if there is a massive mistake in naming them, but based on your lack of release years so far, that might be the reason they don’t show up.
But Demon Slayer is a curious one. It’s interesting to me that, of all shows you have, it’s one of the few that has no subfolders. If there are 2 seasons and you have both, you must have each season included in separate sub folders. If you have both seasons and they are in the root of the folder combined, that may be the reason season 2 is not showing up (check to see if there are duplicates of the season 1 episodes… episodes 1 through 7.)
I’d like to see how your files are named as well. The Naming your media support article linked by FordGuy up above (I can’t stress this enough) should be followed for the files as well. (Personally, I feel you can leave the show name out of the video file names. I never did that, and it never screwed up).
Final word of advice: Follow the show name and release year for shows as seen on https://thetvdb.com/. Plex seems to identify a show and list the episodes based on the information taken from that site.
