When the police or other authority clear a juvenile offender aged 14-19, excluding cases with payment of non-penal fines for traffic violations, the case is to be referred to a family court for offenses liable to fines or lighter punishment, or to a public prosecutor for offenses for which they are liable to imprisonment or capital punishment as well as in general cases (for the definition of juvenile offenders, juveniles of illegal behavior, and pre-delinquents, see Chapter 1 of this Part).
  After the referral, the public prosecutor must carry out the investigation of the case and then refer the case to a family court if any offense is suspected, or if any reason for a hearing at a family court is acknowledged even when there is no suspicion of any offense. When the public prosecutor refers the case to the family court, he/she can offer an opinion on the treatment of the juvenile.
  The public prosecutor may request detention only in unavoidable circumstances in suspected juvenile cases. When such detention is required, a judge may detain the juvenile in a juvenile classification home. Instead of a request for detention, the public prosecutor may request a judge for protective detention for juveniles (commitment to a juvenile classification home). In this case, the juvenile is detained at a juvenile classification home based on the warrant issued by the judge.

  As for juveniles of illegal behavior and pre-delinquents under 14 years of age, priority is given to measures under the Child Welfare Act. A family court may subject such juvenile to a hearing only when it receives a referral from a prefectural governor or a director of a child guidance center.
  Anyone who has discovered a pre-delinquent aged 14 or over should, in principle, notify a family court as to the case. A police officer or a guardian may directly notify a child guidance center as to the case if the pre-delinquent is under 18 years of age, as long as the police officer or guardian deems it more appropriate to handle the case first using measures under the Child Welfare Act than to directly notify or refer the case to a family court.