Rain warning
When you are in an elevator with a group of people, it can suck when the doors open to reveal the outside world that is just pouring rain. People slowly get out of the elevator as they clumsily open up their umbrellas and put on their coats. Not the best place to be.
So again, to make this experience less painful, the Japanese installed a rain warning system in all their elevators, so that people can prepare their umbrellas and exit quickly when the doors open. It just seems like they are all about speed and efficiency considering the way they plan everything to run as smoothly as possible.