Of persons sentenced to imprisonment, those less than20years of age at the time of trial are referred to as juvenile inmates. Sentences for juvenile inmates are executed in juvenile prisons or specifically designated compartments in prisons, to prevent adverse influences from adult inmates and ensure sufficient education and training. Even after they have reached20years of age, the execution of the sentence may be continued in the same places until they reach26.
  As of April1,2000,eight juvenile prisons had been established, namely those in Kawagoe, Mito, Matsumoto, Himeji, Nara, Saga, Morioka and Hakodate.