Updated May 27, 2014.

Definition:

Hikikomori is a phenomenon in Japan, involving withdrawal from society and seclusion in one's home for a period of 6 months or longer. The term, which literally means "withdrawal" in english, can be used both to describe the problem and the person. Some people in this state do not leave their house for decades. The phenomenon is linked to social anxiety disorder (SAD) for some individuals.