I’ve seen little children take the subway alone in Japan. Its a completely different environment
Or walk home from school, or the playground, or wherever they are going from, through the middle of what in any NA city would be described as 'downtown', and would get CPS dispatched on speed-dial.
For what it's worth, this is commonplace in Australia too. I feel like you're describing a general safe country thing. I've lived in Japan so I know it's probably one of the safest places in the world, but I feel like what this thread describes is more US/Canada/some Euro countries being particularly dangerous, and not Japan being uniquely safe.