with the internet and video games.  

It's mostly a reaction to the extreme work-a-holic traditional Japanese culture.  These men realize that they would rather work in order to live than live in order to work.  Some of them will get enough work to sustain them in a simple existence and then quit until they need money again.  What's the point of working, if they are under pressure and stress and have miserable lives ... so they reason.

Young adults may feel overwhelmed by modern Japanese society, or be unable to fulfill their expected social roles as they have not yet formulated a sense of personal honne and tatemae – one's "true self" and one's "public façade" – necessary to cope with the paradoxes of adulthood.  The dominant nexus of hikikomori centres on the transformation from youth to the responsibilities and expectations of adult life. Indications are that advanced industrialized societies such as modern Japan fail to provide sufficient meaningful transformation rituals for promoting certain susceptible types of youth into mature roles. As do many societies, Japan exerts a great deal of pressure on adolescents to be successful and perpetuate the existing social status quo. A traditionally strong emphasis on complex social conduct, rigid hierarchies and the resulting, potentially intimidating multitude of social expectations, responsibilities and duties in Japanese society contribute to this pressure on young adults.^[21] Historically, Confucian teachings de-emphasizing the individual and favouring a conformist stance to ensure social harmony in a rigidly hierarchized society have shaped much of East Asia, possibly explaining the emergence of the hikikomori phenomenon in other East Asian countries.