The Japanese Ministry of Health, Labour and Welfare defines hikikomori as people who refuse to leave their house and, thus, isolate themselves from society in their homes for a period exceeding six months.[1] The psychiatrist Tamaki Saitō defines hikikomori as "A state that has become a problem by the late twenties, that involves cooping oneself up in one’s own home and not participating in society for six months or longer, but that does not seem to have another psychological problem as its principal source."[2] More recently, researchers have suggested six specific criteria required to "diagnose" hikikomori: 1) spending most of the day and nearly every day confined to home, 2) marked and persistent avoidance of social situations, 3) symptoms interfering significantly with the person’s normal routine, occupational (or academic) functioning, or social activities or relationships, 4) perceiving the withdrawal as ego-syntonic, 5) duration at least six months, and 6) no other mental disorder that accounts for the social withdrawal and avoidance.[3]