There is very unusual art in Japan. It is called “inemuri”, and it allows people to be asleep and present at the same time. There is no secret that Japan is a workaholic culture. Thus some people have an amazing talent for falling asleep in elevators, on trains and even during meetings. And this talent is admired, because the Japanese think that only slackers can sleep all night long, others should fall asleep out of exhaustion.
“Inemuri” still requires following particular rules. You can’t lounge, so you should keep upright while sleeping. And you can’t endanger the social situation.
Of course, some people fake “inemuri”. But even when they actually take a nap on the go, they can still maintain their composure. For example, they won’t miss their stop even when being genuinely asleep.
Actually, Japan has one of the lowest crime rates. So yeah, its safe to sleep on the sidewalk wearing a 1000$ suit, its silly but safe :)