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.
Gainax also produced two episodes of semi-biography called 'OTAKU no Video'(OTAKU's video), introducing OTAKU and described the environment of ACG of Japan in the video at that time.
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.
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" , printed in the lolicon magazine Manga Burikko, applied the term to unpleasant fans in caricature.