I was watching a Spanish film just yesterday in which a teenager for no apparent reason suddenly decides not to leave his room any more. Even though it appears to be just a phase, and eventually he does get out, the adults around him begin talking about it as a case of hikikomori, a Japanese term that is being increasingly used to describe such behaviour. It is apparently a fairly frequent occurrence in Japan that a teenager or adult will choose to deal with the harshness of reality by doing just this. Sometimes they stay in their room for years.