Pop diva Madonna once said during her 2005 visit to Japan that she'd "missed the heated toilet seats."
That may sum up the fascination foreign visitors have with Japan's high-tech loos.
And more than a decade later, as Japan prepares for the 2020 Olympics, the technology evolving in its tiny private cubicles is getting so close to perfection that it's changing people's perceptions of what a restroom should be.