You're not challenging them with anything more than personal opinion. Which is fair enough, you're entitled to your opinion, although there are other people living in Japan in this thread who disagree with it.
However, as you're insisting that Japanese-only sources are necessary to consider the claim to be reliable, perhaps you can provide the necessary Japanese sources which contradict it?
The burden of proof is on the accusers. I'm only asking for a single credible source from inside Japan, and in Japanese. Some anecdotes from other commenters is obviously inadequate. I've seen this trope about Japanese police strong-arming people into confessions in all the usual sources for misinformation about Japan on the internet--hence my skepticism. What if the Japanese criminal justice system is just really well run? That is an equally credible conclusion until proven wrong.
This isn't a court of law, and you're not the defendant. There is no "burden of proof."
>I'm only asking for a single credible source from inside Japan, and in Japanese.
Sources from inside Japan and in Japanese have already been posted here. If you find those inadequate, what Japanese language news sources would you recommend? Perhaps you could search those and tell us what they have to report, if anything, on the matter.
>. What if the Japanese criminal justice system is just really well run? That is an equally credible conclusion until proven wrong.
In any other context, with any other country, the police being able to detain and interrogate suspects for weeks and a judicial system with a 99% conviction rate would be assumed to be evidence of unchecked state power. And, of course, "well run" and "systemically corrupt" are not diametrically opposed.
I understand from past comments that you're passionate about fighting against what you perceive as false cultural stereotypes about Japan, which is fine, but in this particular case the assumption being made is that Japan is no different than any other state in the ways that power and opportunity can breed corruption. It can't be "equally credible" to assume that Japan is somehow an exception to human nature.
