The Japanese are very good at rapidly self-organizing themselves. Elevator etiquette is no exception. As an article at Boing Boing explains, they have a system for determining who on an elevator is the "elevator captain", with simple rules of succession, and the elevator captain is responsible operating the buttons on the elevator for maximum efficiency.
Americans tend to think mostly about individual competencies and fail to recognize the extent to which groups can have collective competencies as well, which the Japanese hone far more than we do. Something that is particularly important about these group competency is that unlike individual competencies which are to a substantial extent inherited, and hence can only be improved so much through instruction, group competencies are almost entirely learned and hence can be improved with proper socialization.