Not looking for a debate or anything; their courts are quick and mostly effective because they don't fuck around like courts in the west do. But their police do get extra liberties we try to curtail; I've mostly seen this happen when gaijin start doing retarded shit, but the cops can grab and hold you for like, up to a month, and it can all go away if you just confess. Sometimes you fucked up, sometimes you didn't, but they can hold you and not a damn thing anyone can do; and if you think cool just sweat a month, they can hold you longer and just say it's a different but close enough charge. I imagine it's a lot scarier for foreigners who are visiting or worry about their visa status.
My only real problem with the Japanese justice system is the truth isn't an absolute defense and they still have shades of honor crime; if you say something that can harm another person's reputation, no matter how true it is, you can be held liable for defaming them. You can scream about how true it is and maybe it was even found to be true, you still broke the law by damaging their reputation.
No system is perfect, but we can try to get close.