In the 1970s, most of the land near Narashino was built up due to economic growth, but the Minister of Finance kept one piece of land, a tidal flat, as it was. It was a rare habitat for migratory birds such as plovers and snipes. Water pollution and odor, however, became worse because of illegal waste dumping by people who lived nearby. ​Saburo Morita​who was a newspaper deliverer at that time. He started removing litters in order to clean up the tidal flat by himself. Eventually other people came to help him. They restored mud flat.