The Dōtonbori River, which now flows through Minami(the southern downtown of Osaka City), began as an artificial canal developed by four prestigious local clans, including the Yasui Kuhē, which served as the District Administrator of Osaka’s Minami District. Construction began in 1612 in parallel with urbanization of Osaka by Toyotomi Hideyoshi, and, after a brief halt due to the Seige of Osaka, the canal was completed in 1615 under the order to reconstruct the canal and to development around areas by Tokugawa Shogunate.
The fact that the canal was created by the citizens rather than the government illustrates the pioneering Osaka-style approach to urban development and typifies the spirit of self-reliance and independence in Osaka. This detailed cadastral map, the oldest known record of the township along the Dōtonbori River, is part of the Yasui House Document Collection, a cultural property designated by the City of Osaka. It was discovered in a house of the descendants of Santetsu Yasui, who was go player and relatives of the Yasui House, around 2010.