Otaku (おたく/オタク?) is a Japanese term for people with obsessive interests, commonly the anime and manga fandom. Its contemporary usage originated with Akio Nakamori's 1983 essay in Manga Burikko. Otaku may be used as a pejorative; its negativity stems from the stereotypical view of otaku and the media's reporting on Tsutomu Miyazaki's "The Otaku Murder" in 1989. According to studies published in 2013, the term has become less negative, and an increasing number of people now self-identify as otaku. 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 like Mobile Suit Gundam before 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).