Japan has found a way to clean up or at least mask the dirty and smelly image of sewers. Elaborately-designed and colorful manhole covers now adorn streets across the country. This appeals to be a Japanese love of detail. The history of decorating manhole covers in Japan goes back 40 years as authorities sought to improve the image of the sewerage system. There are some 15 million manhole covers in Japan. Only a fraction have colorful designs.