Sleeping in a street? Nothing is more common in Tokyo.
It could sound a bit strange, but I am referring to the phenomenon(and not unusual) to find young men or salarymen completely collapsed after an evening of beer and sake.
They go sleep anywhere : on a scale , on the ground, on a bench, or underground.
And this happens not only during holidays or special occasions, but also in normal working days.
I do not know the reason for this behavior, but going by logic, I would think that the level of alcohol in their body is so high that they would literally collapse, thus failing to achieve going home or going to sleep in a capsule hotel, for istance.
It is a strange and still entertaining thing, that you can walk around Tokyo and find a serious salaryman with a suit and expensive shoes, sleeping on the floor or even worse a pretty woman in a suit, who is collapsed in a corner of the metro station.
The luck is that Japan is really a safe country, and the risk of any sexual harassment and rapes is significantly lower than in other areas of the world.
The pictures in this article show perfectly this phenomenon.