Persons under age 20 are classified as juveniles in Japan, and the law places them in the following categories: (1) juvenile offenders (persons aged 14-19 who commit offenses under the penal code or special legislation), (2) child offenders (persons younger than 14 and thus not subject to criminal penalties who commit acts which would be criminal offenses if done by an adult), and (3) predelinquent juveniles (persons under 20 who, on the basis of criteria in the Juvenile Law, are believed likely to commit future offenses). The number of juveniles investigated by the police and the rate of juvenile offenders among the juvenile population reached a postwar high in 1980. There is a notable increase in the number of younger delinquents and in the incidence of delinquent pleasure-seeking, along with an increase in juvenile recidivists. There has been notable juvenile violence in the schools and in the homes of juveniles, as well as criminality among 'hot-rodder' groups and drug abuse. Adjudication may be by public prosecutor or family court. Juvenile classification homes conduct prehearing investigations and classification for juveniles referred by the family court. Juveniles may be committed to training schools, juvenile prisons, or given probation. Delinquency statistics are summarized for the United States, the United Kingdom, the German Federal Republic, and France. Japan's delinquency is viewed from an international perspective, and the underlying causes of Japan's increase in juvenile criminality are identified, followed by a listing of countermeasures to prevent delinquency. Tabular data are provided on final dispositions of nontraffic offenders in family courts (1955, 1965, 1975, 1979, and 1980).