Hikikomori is a unique and exclusive phenomenon, characterized by severe social withdrawal, which typically occurs in Japan. Hikikomorian patients are mostly teenagers and young adults who confine themselves inside their parents’ homes for months or even years. They withdraw themselves avoiding any contact with the family, rarely have friends, and do not attend school lessons or perform any work activity. The current nosology of the DSM fails to adequately capture the concept of hikikomori. Differential diagnosis includes anxiety disorders, personality disorders and schizophrenia. Treatment strategies include rehabilitation, family and cognitive behavioral psychotherapy, but their effectiveness is still not supported by sufficient research data. We have studyed the phenomenon in relation to socio-cultural japan aspects but hikikomori may also be found in other contexts.