The behind-the-scenes tales of hit products and creations from Japan: this is Japan's Top Inventions. On this episode, electronic bidet toilets, which clean your bottom with a spray of warm water. On sale since 1980, some 40 million of these toilet seats have shipped, and are now sold in many countries and regions including the U.S. and China. But the creation of this high-tech, revolutionary product was anything but easy. This time, the dramatic tale behind electronic bidet toilets.