Terms used by anime fandom (not all of which are real Japanese words). The links on the left lead to definitions of the term. The links to the right go to the more general term, which is where the examples go.
See also: Japanese Media Tropes Anime Demographics
Hentai -> Means "pervert" or "perversion", used by English fans to label porn. (The usual terms in Japanese are "ero-manga" for comics, and "ero-anime" for animation.)
Ecchi -> The moonspeak pronunciation of the English letter "H", which, in Japan is a catch-all term for naughty stuff, but in the west usually refers to Fanservice-heavy, but non-explicit anime and manga.
Jidai Geki -> Historical drama, usually feudal Japan.
Doujinshi -> Fan comics and fanzines; Fan Fic elevated to its own cottage industry in Japan.
Doujin Soft -> A sub-genre of doujinshi with self-published video games made by indie Japanese game developers; Often considered as fan games as some doujin circles creates games based around popular franchises, although there are some original works as well.
Fujoshi -> The stereotypical female yaoi fan. Literally means 'rotten girl'. See also Yuri Fan.
Lolicon -> A person romantically or sexually attracted to young or young-looking girls (most commonly fictional, even In-Universe). Sometimes used more in a big-brother or big-sister kind of way. Loli usually refers to a young-ish girl instead. Also refers to the genre of media aimed at such people.
Nakama: A group of mostly unrelated people that have bonded into something like a family. Not used that way in Japan.