Prisoners shall be directed to clean up sewage at the Palace and government offices as well as toilets of the east and west on the morning after a rainy night — Collected Interpretations of the Administrative Laws Ryo-no-shuge Selling human waste products as fertilizers became much less common after World War II, both for sanitary reasons and because of the proliferation of chemical fertilizers, and less than 1% is now used for fertilization. Because of this history, Japan had a much higher historical standard of hygiene. For example, in Japan, the orderly disposal of human waste was a common component of the culture. The first Westerner to visit Edo expressed his shock to see such a clean city. In Okinawa, the toilet was often attached to the pig pen, and the pigs were fed with the human waste product. This practice was banned as unhygienic after World War II by the American authorities. During the Azuchi–Momoyama period (1568 to 1600), the "Taiko Sewerage" was built around Osaka Castle, and it still exists and functions today. The use of modern sewage systems began in 1884, with the installation of the first brick and ceramic sewer in Kanda, Tokyo. More plumbing and sewage systems were installed after the Great Kantō earthquake to avoid diseases after future earthquakes. However, the construction of sewers increased only after World War II to cope with the waste products of the growing population centers. By the year 2000, 60% of the population was connected to a sewer system. The national Sewage Day is September 10. Western-style toilets and urinals started to appear in Japan at the beginning of the 20th century, but only after World War II did their use become more widespread, due to the influence of the American occupation. The Occupation government eschewed the use of human excreta as fertilizer, which led to a sense of shame over this practice, and in rural areas where the practice had persisted, human waste quickly went from being recycled to being disposed of. Specific places where night soil continued to be recycled required conscious political leadership, such as the Shinkyō Commune in Nara Prefecture. In 1977, the sale of Western-style toilets exceeded the sale of traditional squat toilets in Japan. Based on toilets with a built-in bidet from Switzerland and the US, the world's largest sanitary equipment company, Toto, introduced the Washlet in 1980. Japanese companies currently produce