According to "Culture and Human Behavior: Culture-Bound Syndromes," the Japanese

According to "Culture and Human Behavior: Culture-Bound Syndromes," the Japanese culture-specific disorder hikkomori is characterized by:

A) extreme social withdrawal, a preoccupation with video games and Internet surfing, an inability to work or attend school, and virtually no social interactions with family or the outside world.
B) an exaggerated concern and preoccupation about minor or imagined defects in appearance.
C) extreme social anxiety because of fear that one's appearance or smell, facial expression, or body language will offend, insult, or embarrass other people.
D) an extreme and irrational fear of experiencing a panic attack in a public situation and being unable to escape or get help.