This is the Lady room. Yes, lady. Just one.
(The image would have been more amusing if I were more inclined to tread toward the realm of the pervert and had actually shot into the restroom, which like many in Japan is of a shallow design that lets you see right in — and in this case would reveal a room with enough room and stalls for quite a few ladies.)
(Also, the no-smoking sign may seem to contradict my previous post about the national obsession with smoking, but bear in mind that cigarettes aren’t nearly as common among the Lady set.)