
A hikikomori is someone who secludes themselves within their home, sometimes refusing to leave their home at all in an effort to isolate themselves from society. It can be viewed as a social phobia similar to agoraphobia. Hikikomori are often associated with otaku but the terms are distinct.
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http://en.wikipedia.org/wiki/Glossary_of_anime_and_manga

==Definition== The Japanese Ministry of Health, Labour and Welfare defines hikikomori as people who refuse to leave their house and, thus, isolate themselves from society in their homes for a period exceeding six months. The psychiatrist Tamaki Saitō defines hikikomori as `A state that has become a problem by the late twenties, that involves coo....
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http://en.wikipedia.org/wiki/Hikikomori

An extreme antisocial phenomenon in Japan (though it has parallels in other postindustrial countries) which involves individuals completely withdrawing from work, school, family, and society in general and holing up in their rooms, often spending all their time playing games, reading manga, watching anime, and/or surfing the Web. It has recently ap...
Found on
http://www.usaanime.us/References/Glossary.htm

Japanese word to describe someone who severely refuses to go out into the daylight.
Found on
https://www.encyclo.co.uk/local/21563
No exact match found.