>>27
http://en.wikipedia.org/wiki/Hikkikomori
Basically, it's a Japanese term to describe a socially uncomfortable, never-leave-the-house shut-in type person...
These types of people first became well known in japan, though it occurs in many countries, as there is a lot of stress constantly over grades, college, work, etc... at a young age, and many people simply become shut-ins because of the stress society puts on them;
Unfortunately, it's become popularized, also overused, some might say, by things like the manga/anime "Welcome to the NHK" (which describes the personal life of a Hikkikomori)... I say overused, mainly as many people love to use the term to refer to themselves & their problems, when in reality they are simply not popular socially, or uncomfortable with social situations, not true hardcore shut-ins who actually break down at talking to another person...