This article attempts to clarify the psychopathological features of "primary social withdrawal". Since the concept of "social withdrawal" in general may include various diseases, we isolated and defined "primary social withdrawal" by excluding cases that could be diagnosed by established classifications of mental disorders. First, we examined two cases of "primary social withdrawal" which could not be classified using DSM-IV. We then compared these patients' psychopathological features to those seen in apathy syndrome, taijin kyofu sho and personality disorders. Based on this comparison, we identified five pathological features of "primary social withdrawal": (1) episodes of defeat without a struggle, (2) protecting the ideal image of the expected self, (3) parents' investment in that ideal self, (4) holding an ideal self image shaped more by the desires of others than those of themselves, and (5) avoidance behavior to maintain the positive opinion of others. Finally, we discuss the socio-cultural background of social withdrawal and possible therapies.