Otaku subculture is a central theme of various anime and manga works, documentaries and academic research. The subculture began in the 1980s as changing social mentalities and the nurturing of otaku traits by Japanese schools combined with the resignation of such individuals to become social outcasts. The subculture's birth coincided with the anime boom, after the release of works such as Mobile Suit Gundam before it branched into Comic Market. The definition of otaku subsequently became more complex, and numerous classifications of otaku emerged. In 2005, the Nomura Research Institute divided otaku into twelve groups and estimated the size and market impact of each of these groups. Other institutions have split it further or focus on a single otaku interest. These publications classify distinct groups including anime, manga, camera, automobile, idol and electronics otaku. The economic impact of otaku has been estimated to be as high as ¥2 trillion ($18 billion).
Otaku is derived from a Japanese term for another person's house or family (お宅, otaku). This word is often used metaphorically, as an honorific second-person pronoun. In this usage, its literal translation is "you". For example, early in the anime Macross, first aired in 1982, the characters Hikaru Ichijyo and Lynn Minmay use the term this way to address one another, until they get to know each other better. The modern slang form, which is distinguished from the older usage by being written only in hiragana (おたく), katakana (オタク or, less frequently, ヲタク) or rarely in rōmaji, first appeared in public discourse in the 1980s, through the work of humorist and essayist Akio Nakamori. His 1983 series An Investigation of "Otaku" (『おたく』の研究 "Otaku" no Kenkyū), printed in the lolicon magazine Manga Burikko, applied the term to unpleasant fans in caricature. Animators Haruhiko Mikimoto and Shōji Kawamori had used the term between themselves as an honorific second-person pronoun since the late 1970s. Supposedly, some fans used it past the point in their relationships where others would have moved on to a less formal style. Because this misuse indicated social awkwardness, Nakamori chose the word itself to label the fans. Morikawa Kaichirō, an author and lecturer at Meiji University, identified this as the origin of its contemporary usage.
Another claim for the origin of the term comes from the works of science fiction author Motoko Arai, who used the word in her novels as a second-person pronoun and the readers adopted the term for themselves. However, a different claim points to a 1981 Variety magazine essay.
In 1989, the case of Tsutomu Miyazaki, "The Otaku Murderer", brought the fandom, very negatively, to national attention. Miyazaki, who randomly chose and murdered four girls, had a collection of 5,763 video tapes, some containing anime and slasher films that were found interspersed with videos and pictures of his victims. Later that year, the contemporary knowledge magazine Bessatsu Takarajima dedicated its 104th issue to the topic of otaku. It was called Otaku no Hon (おたくの本 lit. The Book of Otaku) and delved into the subculture of otaku with 19 articles by otaku insiders, among them Akio Nakamori. This publication has been claimed by scholar Rudyard Pesimo to have popularized the term.
In modern Japanese slang, the term otaku is mostly equivalent to "geek" or "nerd", but in a more derogatory manner than used in the West. However, it can relate to any fan of any particular theme, topic, hobby or form of entertainment. "When these people are referred to as otaku, they are judged for their behaviors - and people suddenly see an “otaku” as a person unable to relate to reality". The word entered English as a loanword from the Japanese language. It is typically used to refer to a fan of anime/manga but can also refer to Japanese video games or Japanese culture in general. The American magazine Otaku USA popularizes and covers these aspects. The usage of the word is a source of contention among some fans, owing to its negative connotations and stereotyping of the fandom. Widespread English exposure to the term came in 1988 with the release of Gunbuster, which referred to anime fans as otaku. Gunbuster was released officially in English in March 1990. The term's usage spread throughout rec.arts.anime with discussions about Otaku no Video's portrayal of otaku before its 1994 English release. Positive and negative aspects, including the pejorative usage, were intermixed. The term was also popularized by William Gibson's 1996 novel Idoru, which references otaku.