Hikikomori is a Japanese term to refer to the phenomenon of reclusive individuals who have chosen to withdraw from social life, often seeking extreme degrees of isolation and confinement due to various personal and social factors in their lives. The term hikikomori refers to both the sociological phenomenon in general as well as to individuals belonging to this societal group.

Although there are versions where the hikikomori may venture outdoors,the Japanese Ministry of Health, Labour and Welfare defines hikikomori as individuals who refuse to leave their parents' house, and isolate themselves away from society in their homes for a period exceeding six months.While the severity of the phenomenon varies depending on the individual, some youths remain in isolation for years, or in rare cases, decades. Often hikikomori start out as school refusals, or tōkōkyohi in Japanese.

In general, the prevalence of hikikomori tendencies in Japan may be encouraged and facilitated by three primary factors:

1. Middle class affluence in a post-industrial society such as Japan allows parents to support and feed an adult child indefinitely in the home. Lower income families do not have hikikomori children because a socially withdrawing youth is forced to work outside the home if he cannot finish school, and for this reason isolation in the room stops at an early stage.

2. The inability of Japanese parents to recognize and act upon the youth's slide into isolation, soft parenting, or even a codependent collusion between mother and son known as amae in Japanese. When a youth withdraws from life, parents can act or respond in such a way that causes the child to become even more seclusionary.

3. A decade of flat economic indicators and a shaky job market in Japan makes the pre-existing system requiring years of competitive schooling for elite jobs a pointless effort. While Japanese fathers of the current generation of youth still enjoy lifetime employment at multinational corporations, incoming employees in Japan enjoy no such job guarantees in today's job market (See Freeters and NEET for more on this). Young Japanese people are savvy enough to see that the system in place for their grandfathers and fathers no longer works, and for some the lack of a clear life goal makes them susceptible to social withdrawal as a hikikomori.

Also, it should be noted that the hikikomori phenomenon is similar to the social withdrawal exhibited by some adults with Pervasive Developmental Disorders (PDDs) in western cultures, a group of disorders that include autism, PDD-NOS and Asperger syndrome. Japan has the highest incidence of PDDs in the developed world, recent epidemiological studies carried out indicate that PDDs affect between 1.2 to 2.2% of children in Japan.

Source : www.wikipedia.org