Hikikomori is a Japanese term used to describe a person who withdraw from society and living in an extreme isolation. The term used to indicate much younger generations who stopped attending school.
According to the survey conducted by the Cabinet Office of Japan, it is estimated that 613,000 aged 40 to 64 fall into the category of hikikomori defined by the government.
Hikikomori is a new concept, not classified as mental illness or disability. Many became hikikomori after their retirement or having failed to adjust to the work place.