Japan enacted a new juvenile code in 1948 and changed to a model that has been interpreted as following the welfare/participatory model due to the emphasis on rehabilitation and the doctrine of parens patriae. Juveniles are defined as those under age 20. The family court has jurisdiction over three kinds of juveniles: (1) juvenile offenders ages 14-19, (2) lawbreaking children under age 14, and (3) pre-offense juveniles under age 20 who are prone to commit some criminal offense. The three peaks of juvenile delinquency in recent decades occurred in 1951, 1964, and 1983. An increase in thefts contributed to the third peak. Bullying activities in the schools received national media attention starting in 1985. Sex offenses have decreased during the last three decades. The use of drugs such as cocaine and heroin is not regarded as a serious problem in Japan, although methamphetamines have been prevalent since the end of World War II. Youths ages 14-15 have the highest rate of non-traffic juvenile offenses because of the intense competition for opportunities in higher education. The juvenile justice administrative process involves many steps and includes many programs. Current issues include the difficulty in guaranteeing due process in the welfare/participatory model; the advantages and disadvantages of net widening efforts; and the probable excessive protection, guidance, and supervision of youth by adults as their proportion of the population continues to decline. Tables, figure, and 45 references