This is a group of Sue ware kiln sites located in the hills of southern Osaka. The kiln sites cover an area of 15 km from east to west and 9 km from north to south, extending from the area around Sayama Pond, which is mentioned in the Chronicles of Japan, to the hills to the east of Kumeida Pond in the west. According to the current administrative division, the area covers Sayama-cho, Sakai City, Izumi City, and part of Kishiwada City in Minami-kawachi-gun, Osaka Prefecture. The distribution of kiln sites is centered around the former Nishi Touki and Higashi Touki villages, and the density of distribution gradually decreases in the surrounding areas. In the Doueup kiln site group, we have discovered more than 500 Sue ware kiln sites that were constructed between the 5th and 10th centuries, and if we add the unidentified ones that have already been destroyed or not yet discovered, the total number is probably more than 1,000. This kiln site group is the oldest in Japan and the largest in scale as the center of ceramic production before the Nara period. The name of the Tōeup kiln site is based on the name of the place “Tōeup, Chinu” mentioned in the 7th year of Emperor Sojin’s reign in the Nihon shoki (Chronicles of Japan), Vol. 5. Chinu is the ancient name for the area around Hannan, which is often mentioned in the “Chronicles” as “Chinu-no-Agata-no-Sue-no-murasu”, also written as “Kennuma”, “Chen-nu”, “Chin”, and so on. Toueup literally means “village of sue-no-Mura,” and refers to the village of potters. According to an article in “Nihon shoki” (Chronicles of Japan), Toueup was located in Chia-nu-hyeon. Therefore, the name “Toueup” refers to the village of Sue ware producers in the southern part of Osaka, and the kiln sites left by the potters of Toueup can be found nowhere else but in the area of the Hannan Hills, giving this kiln site group the name “Toueup Old Kiln Site Group”. The Hannan Hills, where the kiln sites are located, are backed by the Kongo Mountains and the Izumi Mountains, and in front of them is a narrow plain facing Osaka Bay. The elevation of the hills where the kiln sites are located is between 40 and 200 meters, and the strata that make up the hills are the Osaka Formation, which is widely distributed in the surrounding areas of the Osaka Plain. This formation is composed of gravels and clays with relatively low coagulability, and was deposited from the end of the Tertiary Pliocene to the Quaternary Pleistocene. The kiln site was constructed based on freshwater clay layers or terrace deposits in the Osaka Group. The kiln structure is a cellar kiln, common to Sue ware kilns, from the establishment of the Toei kiln to the end of its life. The size of the kiln body varies slightly depending on the period, but the most common kiln body is about 10 meters long and the maximum width of the floor is about 2 meters. Most of the kilns in the Tōyū kiln have a semi-underground structure, and there are no examples of kilns constructed entirely in the gouged style, from the firing chamber to the smoke outlet. However, there is a kiln dating from the 8th century that was constructed with the majority of the firing section in the gouged-out style, with the burning section added to the gouged-out structure. The production of Sue ware began in the middle to late 5th century at Tōei. The shapes, patterns, and production techniques of early Sue ware are strongly related to those of ceramic earthenware from the Korean Peninsula. For the first 40 to 50 years after the Dou-eup kiln began operation, Dou-eup was the only Sue ware production site in Japan.
The products of the Doueup kiln were the only Sue ware production site in Japan. The products of the Doueung kiln were supplied to all parts of the country, either through the hands of the central authorities or through the hands of the powerful families who controlled the potteries. Some of the products from this period were transported as far away as Tsushima. However, since the Sue ware production sites that were established in the regions were all small and the supply area was narrow, the Tōei kilns continued to expand and develop even after the establishment of the regional kilns, and continued to maintain their position as the center of Sue ware production in Japan. The Douup kilns continued to expand and develop after the establishment of the local kilns, maintaining their position as the center of Sue ware production in Japan. Throughout its existence, the Dōeung kiln reached its peak in scale around the latter half of the sixth century. Among the products, small octopus pots and other vessels used in production appear, indicating the development of economic exchange through direct exchange of products with fishermen from the neighboring Osaka Bay coast.
From the end of the 6th century to the beginning of the 7th century, significant changes appeared in all aspects of Sue ware production in pottery kilns, including the structure of the product kilns. The number of high cups, which had been produced actively in the past, declined sharply, and certain types of potteries, such as jar-shaped earthenware, vases, and side vases, almost disappeared. On the other hand, new types of vessels, such as vessels, plates, bowls, long-necked jars, and flat bottles, appeared, completely changing the combination of vessel types. In addition, many vessels of the same type have undergone a complete change in form. Corresponding to the changes that appeared in the products, remarkable changes can also be seen in the structure and construction methods of Sue ware kilns. Kilns of the 5th and 6th centuries were usually used for a long period of time, and the walls were repaired many times and the floors were stacked in layers. However, after the beginning of the 7th century, kilns with only one wall and one floor became overwhelmingly common. This means that, as a result of advances in kiln construction technology, kilns were freed from the constraint of having to use a single kiln for a long period of time. The Touyuu kilns gradually began to decline from the latter half of the 7th century onward.
In the Nara period (710-794), large-scale ceramic production sites emerged in the Tokai region, and local kilns in each region expanded and developed, and as a result, the Doueup kilns lost their position as the center of ceramic production, falling to that of a local kiln in the Kinai region in terms of both quality and quantity. However, the production of Sue ware continued until the 10th century without ceasing. The Toei kiln produced only Sue ware for about 500 years from its establishment to its demise, and there is no evidence that it fired tiles or other ceramics. Although tile kilns appeared in many places after the 7th century, they were characteristic of local kilns, and potters and tile makers were originally completely separate families.
