Just checked out samachan.
Rule 7. All images and discussion should pertain to anything Japanese. This includes, but is not limited to: Anime, Manga, Doujinsoft, Japanese Videogames, Light Novels, etc. Users who post images that are non-Japanese related could have their images deleted and may receive a ban.
Original content or content created by westerners relating to Anime, Japanese videogames, or more, is acceptable content. Western culture, memes, politics, etc., is not. If you drew a picture of your favorite anime character, this is certainly allowed to be posted.
Mixed feelings about this. On the plus side, it cuts down on politics. But overall it's too limiting; for example there's a thread on /z/ about cute chairs and being restricted to anime or even Japanese chairs will likely hinder the thread.