Probably the same pretty much anywhere in the world. I have a hard time imagining a kid asking an adult for help and the adult refusing, even if it's a stranger.
I have a hard time imagining a kid asking an adult for help. "Never talk to strangers," was the takeaway I got from elementary school. "Never tell an adult who you don't know where you live unless they know your codeword your parents shared with you" (in this case, the password was 'skateboard'.)
If the kid is too shy to ask for help or has been taught never to talk to strangers, then they would never even attempt to approach a stranger. Seems like that's the main difference: that Japanese children are taught to trust the community they live in.