This leads to a two-pronged result: on the one hand, only the best cases should be followed up on and brought to court. Depending on the statistics, about every other case (~50%) is not followed up on by the prosecutionabout every other case (~50%) that the police investigators hand to the prosecution is not followed up on by the prosecution. The other result is, that the Japanese justice system relies heavily on confessionsthe Japanese justice system relies heavily on confessions obtained from the defendants.
This has its problems too: Because the prosecution is notoriously overworked, citizens with problems are often more reluctant to bring cases to their attention. Further, the shame culture works against not just the perpetrators, but also the victims and the people that report certain crimes - for example, a female police officer was groped on a train, and when she reported it, she became the target of shunning.