Otaku is derived from a Japanese term for another's house or family (お宅, o-taku), which is also used as an honorific second-person pronoun. The modern slang form, which is distinguished from the older usage by being written only in hiragana (おたく) or katakana (オタク or, less frequently, ヲタク), or rarely in rōmaji, appeared in the 1980s. In the anime Macross, first aired in 1982, the term was used by Lynn Minmay as an honorific term. It appears to have been coined by the humorist and essayist Akio Nakamori in his 1983 series An Investigation of "Otaku" (『おたく』の研究, "Otaku" no Kenkyū), printed in the lolicon magazine Manga Burikko. Animators like Haruhiko Mikimoto and Shōji Kawamori used the term among themselves as an honorific second-person pronoun since the late 1970s.
In modern Japanese slang, the term otaku is most often equivalent to "geek". However, it can relate to a fan of any particular theme, topic, hobby or any form of entertainment.
The former Prime Minister of Japan Taro Aso also claimed himself to be an otaku, using this subculture to promote Japan in foreign affairs.
On the matter, in recent years "idol otaku" are naming themselves simply as wota (ヲタ) as a way to differentiate from traditional otaku. The word was derived by dropping the last mora, leaving ota (オタ) and then replacing o (オ) with the identically sounding character wo (ヲ), leaving the pronunciation unchanged.
When otaku are studied, female otaku are largely ignored. Reki-jo are female otaku interested in Japanese history.
The term is a loanword from the Japanese language. In English, it is usually used to refer to an obsessive fan of anime/manga and/or Japanese culture generally, and to a lesser extent Japanese video games.
The term serves as a label similar to Trekkie or fanboy. However, use of the label can be a source of contention among some anime fans, particularly those who are aware of the negative connotations the term has in Japan. Unpleasant stereotypes about otaku prevail in worldwide fan communities, and some anime fans express concern about the effect these more extreme fans can have on the reputation of their hobby (not unlike sentiments in the comic book and science fiction fandoms).
The term otaku is close in connotation to the English nerd, but the closest English-language analogue to otaku is probably the British English term anorak. Both of these English-language terms have more emphatically negative connotations of poor social skills and obsessive interest in a topic that seems strange, niche or boring to others. It is not applied to a socially awkward intelligent person who appears fairly "normal," and merely has an interest in certain typically 'geekish' pursuits (video games, comic books, computers, etc.).
While otaku in English-speaking contexts is generally understood to mean geek or even fan, this usage is not widely known in Japan and hence casual use of the term may confuse native Japanese speakers. Self-identification as an otaku may seem strange to them, and they may be offended if a non-Japanese speaker calls them an otaku.
In Japan there has been some negativity towards otaku and otaku culture. Tsutomu Miyazaki became known as "The Otaku Murderer" in 1989. His bizarre murders fueled a moral panic against otaku.
In 2004, Kaoru Kobayashi kidnapped, sexually assaulted, and murdered a seven year old first-grade student. Japanese journalist Akihiro Ōtani suspected that Kobayashi's crime was committed by a member of the figure moe zoku even before his arrest.
Although Kobayashi was not an otaku, the degree of social hostility against otaku seemed to increase for a while, as suggested by increased targeting of otaku by law enforcement as possible suspects for sex crimes, and by calls from persons in local governments for stricter laws controlling the depiction of eroticism in materials which cater to some otaku (e.g. erotic manga and erotic videogames).
"Otakon" (short for "otaku convention") is a convention organized by Otakorp, Inc, a non-profit organization. Otakon is focused on anime, manga, East Asian culture, and its fandom. The second largest convention of this type in the US and the largest on the east coast, it began in State College, Pennsylvania, in 1994 and has been held in Baltimore, Maryland since 1999. Currently, the largest convention of its kind is Anime Expo which takes place in Los Angeles annually.
Otakorp Inc. gave permission to Konami to use the name "Otacon" in any of their Metal Gear video game series. "Otacon" is the codename of character Hal Emmerich, a scientist and self-professed otaku.