When we talk about representative ceramics of the medieval period, the first things that come to everyone’s mind are the yellowish-green or blackish-brown glazed Kosedo pots and vases decorated with various designs. On the other hand, however, we also have no hesitation in naming Old Tokoname, with its wild beauty of dark green glaze running down the rough brown surface, or Atsumi pots and jars decorated with distinctive designs. These two completely different types of pottery, glazed and unglazed, share each other’s functions and constitute the basis of medieval pottery. Furthermore, the Shirashi ceramics that fired unglazed bowls, plates, and bowls that spread throughout the Tokai region, including Seto, Tokoname, and Atsumi, and the red unglazed earthenware from the Kofun period that existed at the base of these ceramics were also major living vessels that played a part in medieval pottery. Recently, in addition to these well-known ceramic sites, glazed ceramics similar to those of Kosedo and jars similar to those of Tokoname have been discovered in the Tokai region, showing the extremely complex nature of medieval ceramics.
These medieval ceramics were all produced at the same time in the late Heian period, i.e., around the beginning of the 12th century. The process of establishment of each ceramic production site will be discussed in the individual explanations, but aside from Seto Mino, which was the only production site of glazed ceramics in Japan, the medieval pottery kilns in Nyokami are characterized in that they all fired jars and mortar, as well as unglazed bowls and plates. These ceramics were newly emerged as necessities in rural life, in a form different from that of the previous period.
In this volume, I would like to point out in advance the position of the products of the Tokai kilns, excluding Seto and Mino, in the medieval ceramic art. As I have often mentioned, medieval pottery can be categorized into three types: earthenware, Sue ware: and japanned ware.
The earthenware type includes both earthenware itself and tile ware, the former of which functioned primarily as a boiling tool in the Middle Ages. The former functioned mainly as boiling utensils in the Middle Ages, while the latter was used for daily tableware such as bowls and plates produced only in western Japan. The Sue ware type includes Bizen ceramics, which were produced in the Heian period (794-1185), but were transformed into brownish-brown ceramics by oxide firing during the Kamakura period (1185-1333), and Suzu ceramics, which are grayish-black in color and were produced by reduction firing, following the Sue ware production techniques, and tile-like ceramics from western Japan such as Kameyama. Finally, in the ceramic ware category, there are (1) Seto Mino (Minosue kilns and Tono kilns) as glazed ceramics that are descended from the Heian-period shirashi lineage, (2) Shirashi ware kilns in the Tokai region that fired unglazed daily tableware and some storage containers, (3) Tokoname, Atsumi, Kosai, Kanesan, Nakatsugawa, etc., which mainly produced jars, pots, and mortar, and (4) Shirashi ware kilns in the Heian-period, which have no tradition of shirashi production. (4) Echizen, Kaga, and Sasagami (Niigata Prefecture), and Tohoku and Shinanoura (Miyagi Prefecture) in the Tohoku region, and Shigaraki Tamba in western Japan, which were influenced by Shirashi ceramics from the Tokai region and transformed into medieval kilns in the Hokuriku region, which had no tradition of Shirashi production in the Heian period.
So, what types of ceramics were fired at the ceramic sites mentioned above? While all three areas share the same Heian-period Shirashi tradition, the products produced in (1), (2), and (3) are different from each other. Of the ceramics included in (1), Mino, with the exception of the Kosedo-style glazed ceramics of Tono, uses glazes of different characteristics, but in terms of vessel form, its products are similar to those of Seto. In other words, Mino has a richer variety of ceramics than the ceramic sites (2) and (3), including bowls, plates, bowls, and bottles for tableware, one-port mortar bowls for cooking utensils, and jars and pots for storage containers. In contrast, the Shirashi ceramics kiln in (2) mainly fired bowls and plates as daily tableware for farmers and mortar and pans as cooking utensils, and some of them also fired Buddhist altarware and roof tiles. Kilns in Tokoname, Atsumi, Kosai, Kaneyama, Nakatsugawa, and other areas mentioned in (3) include bowls and plates as tableware, ground bowls as cooking utensils, and kataguchi, but their main products are large containers such as jars.
Why did these regional variations occur in the tradition of the Heian period’s Shirashi? This is the result of a division of labor based solely on differences in the clay used.
Next, let us discuss the production techniques of medieval ceramics of the 瓷器 type. A major reason why the Tokai kilns, centering on Seto and Tokoname, have continued to develop as large ceramic centers since ancient times is that they were blessed with high quality, highly refractory clay. As is well known, the low hills from Seto to Mino have abundant deposits of high-quality clay called Mokusetsume clay, which is a kaolin-type mineral contained in the Pliocene Seto Pottery Clay Formation and the Yada River Formation based on the granite matrix underlying Mount Mikunisan Sanage and Mount Yatae, and is highly refractory and dense, They were highly refractory, dense, and plastic. They are suitable for the production of glazed ceramics that require high firing temperatures, and were the reason why the Shirashi glazing technique survived in the Tono area until the introduction of the Kosedo glazing technique. On the other hand, the clay of the Chita Peninsula is kaolin clay from the Tokoname Group of the Yada River Formation, which is based on the granite of Sanageyama, and is slightly less refractory, making it suitable for the production of large jars and pots. The area where the Sanage and Minosue kilns were distributed is geologically in between these two types of clay, making it suitable for the production of unglazed white porcelain. The abundance of potter’s clay distributed over such a vast area with a long north-south axis, and the fact that its characteristics varied according to the order of deposition and distance from the host rock, made it possible to fire ceramics suitable for each region in a division of labor.
The molding techniques varied according to the type and size of the vessel, but the basic techniques used were wheel-thrown water-ground and clay-wrapped molding. With the exception of Seto Mino, these ceramics generally have no decoration on the surface of the vessel, except for the three-stripe pattern decoration in the very early stages. Next, looking at firing techniques, all of the jushi ware kilns are based on the same kiln body structure. In other words, the basic structure was a wide, large-volume kiln body excavated near the top of a hillside, with a thick flaming column at the border between the combustion chamber and the firing chamber. This type of kiln structure was found only in the Tokai region and parts of the Kinai region. Even though the kilns in the Tokai region have basically the same kiln structure, there are differences in the details depending on the nature of the clay used. In the case of Seto Mino, where highly refractory clay is used, the floor of the firing chamber is slightly higher toward the back, but in the case of Atsumi, where coarse clay with low refractoriness is used, the firing chamber slopes down considerably from the fire mouth to the firing column, thus adopting a kind of indirect firing method.
-Now, the ceramics discussed in this volume can be functionally divided into three main categories. These are: Mino white porcelain ceramics, excluding Kosedo type glazed ceramics; unglazed bowls, plates, and bowls as tableware for the general public fired at white porcelain kilns spread throughout the Tokai region; and jars as large storage containers fired in Tokoname, Atsumi, Kaneyama, Nakatsugawa, and other locations. Of the above, the content of Mino white porcelain-type glazed ceramics has only recently become clear, and some explanation will be given at the end of this section. The second type, unglazed bowls, plates, and bowls, were produced in large quantities in all of the above ceramic centers and formed the basis of medieval ceramics. In contrast, large jars, pots, and mortar were characteristic of medieval pottery, and their medieval significance lies in the fact that they were clearly identified in Tokoname, Atsumi, and other areas prior to Seto. Looking at the functions of these three types of vessels, it goes without saying that jars have been developed since Sue ware as general storage containers. However, it is important to note that in the Middle Ages, jars were closely related to agriculture, as shown by the term “seed jar. In addition to the storage of seed rice for sowing, it should be considered to have the function of soaking seed for sowing. With the spread of double cropping since the end of the Heian period (794-1185), soaking rice before sowing is thought to have had a significant impact on the growth of the rice plant. Jars are also indispensable storage containers in daily life, originally used as water jars or for brewing sake, but with the development of fertilizer cultivation technology in the Middle Ages, the function of jars as fertilizer jars is thought to have increased. The main type of fertilizer gradually used after the Heian period (794-1185) was grass and wood ash, but in the Kamakura period (1185-1333), the use of manure is thought to have begun. The suribachi, also called a large flat bowl, was an all-purpose cooking utensil that was indispensable in daily life. All three types of vessels are unique in that they were daily miscellaneous vessels and deeply connected to agriculture.
Then, why were these large jars and pots produced in the central peninsula of Tokoname and Atsumi, far away from the Sanage kilns of the late Heian period? One reason is the nature of the clay. As explained in the Tokoname section, the central peninsula around Tokoname is an area where black clay is predominant among the so-called Tokoname clays, and this low refractory black clay is suitable for firing large jars and pots. The hilly area in the center of the peninsula, which is the narrowest in width from east to west, was close to the coast, making it extremely convenient for transportation by boat. This is also true on the Atsumi Peninsula.
Large jars from Tokoname were transported and used almost throughout Japan, from as far away as Aomori Prefecture to Kagoshima Prefecture. In other words, in addition to the excellence of the products based on the traditional techniques of the previous generation of Shirashi porcelain, the convenience of boat transportation was a major reason why Tokoname developed into a major ceramic center ahead of the rest of Japan. It should be noted that the Atsumi kilns were under the same conditions.
However, the products of Tokoname Atsumi were not limited to the production of miscellaneous farmer’s wares. Among the sutra casing outer vessels found in sutra mounds around the area, and among the bone implements excavated from medieval cemeteries, there are some high quality items with designs in the three-stripe pattern. The medium-sized sutra jars from Tokoname and the carved jars from Atsumi are by no means jars of a miscellaneous nature. For example, the san-suji jar, which is said to be a Tokoname specialty, is not religious in the sense of the five-ring cycle, but rather an abbreviation of a type of jar with a double-line three-suji pattern that was already produced at the Sanage and Minosue kilns in imitation of Chinese Song dynasty white porcelain four-lobed jars. The same is true of jars with carved designs at Atsumi. In addition, large vases with a series of patterns, such as jars with a design of autumn grasses, can all be traced to large vases made in imitation of Chinese wide-mouthed vases at the Sanage kilns of the previous period. It is a noteworthy fact that Chinese ceramics had an influence on Tokoname and Atsumi, but unlike the Seto kilns, which were faithful imitations of Chinese ceramics, the fact that they were transformed into something unique shows the unique world of these ceramic industries, which were connected to the central aristocratic society.
Finally, I would like to make a few remarks about the Minosue kilns, which can be called a variant of the first type of the 瓷器 series. The Minosue kilns were the center of Sue ware production in the Mino Province, which stretched from Gifu City to Kakamigahara City, and in the 10th century, they introduced the production techniques of Owari Shirashi, and switched to producing Shirashi.
In the 12th century, production of this Mino Sue ware ceased, except for a small area in the east, while other areas producing white porcelain turned to unglazed bowl and dish kilns. However, it is now known that ceramic production in some of these eastern areas has noteworthy contents. In the eastern hillside of the Inadayama Kiln Site Group at the eastern end of the Mino Sue Kiln, the discovery of old kiln sites that produced unglazed bowls and plates as well as four-mimi jars and earthenware bottles with ash-glazed shoulders similar to those of Kosedo raises a new issue.
These four-mimi jars were previously vaguely referred to as being fired at Seto or near Seto, and there have been quite a few discoveries of them from various locations in the Tokai region. The Inadayama ware dates from the middle of the Kamakura period (1185-1333), but the four-mimi jars of the same type that have been discovered in various places in recent years range in age considerably, and those excavated from the Okunoin Temple at Koyasan and the sutra mound at Kahoji Temple in Niigata Prefecture show forms that may date back to the latter half of the 12th century. Therefore, there are still several undiscovered kilns of the same type in the Mino Sue kiln. This type of four-eared jar is believed to have been fired not only at the Minosue kiln but also at the western part of the Sanage kiln, and its prototype is a white porcelain four-eared jar of the Song dynasty, which was introduced to Japan in large numbers at that time. The Higashiyama Kiln in the western part of the Sanage Kiln was eventually succeeded by the Seto Kiln, but the development in Mino was different from that in Owari in that the white porcelain technique continued to be used. Eventually, in the Nanbokucho period, the Kosedo style of glazed ceramics was replaced by the Kozeto style.
Tokoname
Jars and pots with a bright green natural glaze running down the reddish-black surface are representative of medieval Tokoname ware. The ruins of old kilns where these jars and pots were fired cover the entire Chita Peninsula, centering on Tokoname City, and are collectively called the Chita Peninsula Old Kiln Site Group. Surprisingly early research on old Tokoname was already started in the 20th century by Shinichi Terauchi, Teiichi Takita, and others, but it was not until after the war that full-scale research based on the excavation of old kiln sites began. Starting with a distribution survey of the entire peninsula by the Tokoname Kogama Research Group led by Yoshiharu Sawada in 1952 and the excavation of the No. 1 Kiln at Kagomeike, excavation surveys conducted by Nagoya University from 1949 to 1961 in conjunction with the construction of the Aichi Waterworks and numerous civil engineering projects by local researchers from around that time to the present have led to the excavation of over 100 kiln sites. The results of these excavations have been used as the basis for a system of paleo-Joname dating from the late Heian to the Muromachi period. The kiln sites of Paleo-Joname from the late Heian to Muromachi periods are distributed almost all over the peninsula, and currently more than 50 groups with over 1,300 kiln sites have been identified. The distribution density of these kiln sites is not uniform, with only a few kilns located in the western half of the central area near Tokoname City and a very small number of kilns at the tip of the peninsula south of Noma Town, where the stratigraphy is different. This group of more than 50 old kiln sites also includes several branch groups, ranging from three to four small kilns to 30 large kilns. The most densely distributed of these groups are the Handaike kiln site group in the central part of the peninsula, the Shibayama kiln site group in the northeastern part of Tokoname City, and the Shiinoki Hinoharayama kiln site group in the southeastern part, which alone account for the majority of the total. The products of each kiln are not uniform, and there are two types of products: jars and pots and mountain tea bowls and small plates. The former is predominant in the Tokoname City area, while the latter tends to be found in the northern part of the peninsula. The difference in the distribution of the two types is closely related to the occurrence and development of the pottery and the distribution of the clay used.
Chita Koyo products include bowls and plates as tableware, bowls and pots as cooking utensils, jars and pots as storage containers, ritual implements, stationery, fishing tools, roof tiles, and various other items, but the main items are two types of sets: jars, pots, and mortar, and mountain tea bowls and small plates. Especially, the term “Ko-Tokoname” refers to the former, and there is a division of labor between Ko-Tokoname and Seto, which mainly produces high-grade glazed ceramics. The Yama-chawan (mountain tea bowls) and small plates are the base ware covering the entire Tokai region. The set of mountain tea bowls and small plates is a descendant of the set of medium-sized bowls and small bowls in ash-glazed pottery of the late Heian period and the small bowls lost their high bases and became small plates in the Kamakura period, and is the most common combination of tableware widely used among the people. There are two types of bottles. One is a water jar as a Buddhist vessel, which has been handed down from Heian-period ash-glazed ceramics, and is characterized by the loss of the base and the protruding band at the junction of the neck and shoulder. The other is a wide-mouthed jar also from the previous period. The large jar has a butt strap as in the water jar. There are several types of jars. The most common types are wide-mouthed jars (about 25 cm high), short-necked jars of various sizes, and large jars with narrowed necks, many of which have three or four ring ears. Unique to Tokoname are the so-called “three-stripe” jars, in which the body of a wide-mouthed jar is decorated with three chink lines. There are also small numbers of small one-necked jars from the late Kamakura period (1185-1333). Most of the large jars are 50-70 cm in height and body diameter, and are characterized by the fact that the folded edges of the rim became wider with time. The small jars are 30-40 cm tall, and the change in the rim band is similar to that of the former type. In addition, a wide-mouthed small jar named fushiki jar was made in the Muromachi period (1336-1573). A suribachi is a commonly used large flat bowl with a one-sided opening at the mouth rim. There is also another type of one-edged bowl with an inside rim. In addition to the above basic items from Ko-Joname, there are various other items such as tsubagama, inkstones, pottery rounds, pottery weights, weights, dice, and ritual implements. In addition, along the central dorsal ridge of the peninsula, there is a long north-south line of kilns where tiles were fired together.
Next, let us look at the production techniques of Ko-Joname. The pottery clay used in Ko-Tokoname is kaolin clay from the Tokoname Group, which belongs to the Neogene strata distributed throughout the peninsula. The Tokoname Formation is contrasted with the Owari Lignite Formation and the Ino High Formation in the upper Pliocene, which are derived from the granite of the Osan Border, and covers a wide area from the northern to central peninsula. The southern tip of the peninsula is composed of alternating layers of shale and sandstone of Miocene age, and the Tokoname Formation overlies the shale in places. Thus, the entire peninsula is a source of pottery clay. Tokoname clay is divided into two types, white clay and black clay, according to the difference in iron content. White clay contains 2.51% iron and black clay 13.92% iron. The latter has a low refractoriness and can be fired at low temperatures, making it suitable for the production of large jars and pots. This difference in clay distribution is the reason why most mountain bowls are produced in the north and most jar/pot kilns are concentrated in the central region. In the very early stages of pottery production, wheel-thrown water-grinding pottery techniques, which have been used since the Heian period (794-1185), were still in use, but basically, jars and pots were made by winding up clay strings. In particular, large jars were formed by adding thick clay cords called “yoriko-zukuri,” which went around the jar and formed a five- to seven-tiered ring. Except for a few special types of Ko-Joname jars, such as san-suji jars, there are only a few examples of Akikusa-style carved patterns in some areas in the very early period, but as a general rule, these jars are unmarked.
Rarely, a small sealed floral motif is found on the shoulder of the jar. In the Heian and Kamakura periods, large jars had various seals placed around the joints during the molding process, but in the Muromachi period, only traces of these seals are found on some of the surfaces of the vessels. The kiln used for firing belongs to a type of cellar kiln excavated deep underground on a hillside, and has a structure unique to the Tokai region with a dividing pillar at the border between the firing chamber and the burning chamber. The floor of the firing chamber varies according to the refractoriness of the clay used. The floor of the white clay is horizontal, while that of the black clay, which is less refractory, slopes down toward the inside of the chamber. Therefore, the firing chamber is often at a steep angle. This is probably done to prevent damage to vessels caused by direct firing. In each case, after the kiln was filled, firing tables were piled up on both sides of the firing chamber to form a barrier to reduce the size of the flame vent. The flue is inclined at a different angle to the firing chamber to bring it closer to the horizontal, and clay rods with a diameter of 10 cm or less, each wrapped in a layer of tinned clay, are placed along the border between the two to seal the firing chamber. Kilns drilled deep into the ground often have a humidity drainage facility under the floor to prevent groundwater from seeping in, using either mountain bowls or wood. The sanchawan kiln is usually 6 to 8 meters long and 2.5 meters wide, with a horse claw-shaped firing stand placed on the floor to create a horizontal surface on which 13 pieces are stacked for firing. In most cases, the firing table is placed in 16 rows and 20 columns, and thus the amount of pieces fired at one time is around 4,000. The length of a jar/pot kiln is about 12 m and the width is about 3 m. However, a large jar from the late Kamakura period was over 14 m long. Three rows of nine large jars are arranged in the lower half of the firing chamber, and the upper half is used for mortars and small jars.
When and how did the Tokoname kiln originate? The details are not yet clear, but it is not difficult to imagine that it was the mother kiln of a branch of the southern part of the Sanage kiln in the late Heian period. The southern branch of the Sanage Kiln ash glaze pottery kiln extended to the northern part of the Chita Peninsula in the late Heian period, around the end of the 11th century, but some of these potters moved to the central part of the peninsula, around the foot of Mt. It is known that the oldest jars and pots are concentrated in the Shiinoki and Hinoharayama ancient kiln sites in the same area. The oldest known Ko-Joname product is a sanjiki-jar excavated from under a Shiho-Butsuishi (Buddhist stone) inscribed in 1125, the second year of the reign of Tenji (1125), from the Ikkyozuka mound in the precincts of Imamiya Shrine in Kyoto. It is not clear why the production of jars and pots began in the central part of the peninsula, but one reason is the distribution of pottery clay suitable for their production, and another is that the area was close to the coastline, making it advantageous for the transportation of large jars and pots. As described above, the Chita kiln site group shows a dual development, with bowl kilns moving southward from the northern part of the peninsula, while jar and potteries spreading from the central part of the peninsula to the north and south.
Ko-Joname is known to have undergone seven stages of transition from the end of the Heian period to the late Muromachi period (the chronological chart on page 94 illustrates up to six stages). The first stage is marked by Kiln No. 1, Yamaki, Ogawa Shinden, Higashiura-cho, Chita-gun, and Kiln No. 2, Matsubuchi, Tokoname-shi, but there is a slight time gap between the two. As mentioned earlier, Ko-Joname has differentiated between mountain bowls and jar kilns from the beginning, but in this first stage, there was still some mixing and firing of both types, and many of the products are of high quality. Many of the products are of good quality. Many of them still retain the connection with the ash-glazed ceramics of the previous period, such as the ring-flower technique used in bowls and bowls, and the glazing technique seen in jars and pots. Many of the jars and pots still retain the water wheel throwing technique, and the mouth rims of the jars and potteries are sharply made. The second stage is marked by Kiln No. 2, Togamine, Agui-cho, Handa City, and Kiln No. 3, Kago-ike, Ono-cho, Tokoname City, and dates from the end of the Heian period to the beginning of the Kamakura period. The third stage is marked by Kiln No. 2 at Taya Kiln in Tokoname City, which belongs to the middle of the Kamakura period. Between the second and third stages, Tokoname kilns developed rapidly and spread to almost all areas of the peninsula, including the mountain tea bowls. Jar and jar kilns also spread to Dongoura Town in the northern part of the peninsula, and the division of labor between mountain tea bowls and jars and jars became more coarse-grained, with small bowls becoming a set of bowls and plates, while large bowls and small bowls were clearly divided into small bowls and jars. As the jars and pots became larger with the coarsening of the clay used, the folded rim band at the mouth rim became wider to protect the mouth rim. The fourth stage is from the late Kamakura period to the Nanbokucho period, and is marked by the Takasaka large kiln in Tokoname City and the Tatsumigaoka No. 2 kiln in Chita Town. Kilns larger than 14 m in scale were seen in various locations, and large jars with a height and body diameter of over 70 cm were mass-produced during the heyday of Ko-Joname. The division of labor by vessel type was further advanced, and the number of wide-mouthed jars, which had existed since the Heian period (794-1185), disappeared, and the number of water jars also decreased drastically. Bowls and plates became coarser and less bulky. Jars, pots, and mortar were produced under the division of labor, and the largest vessels were produced in this period. The fifth stage is from the late Nanbokucho Period to the early Muromachi Period, and is marked by the Tenjin No. 4 kiln in Tokoname City. From this period, the number of kilns gradually began to decrease and became concentrated in the Tokoname City area. The scale of the kilns also began to decrease, but the large type of kilns continued to grow in size, with wide mouth rims over 1 m in height being produced. The number of mountain tea bowl kilns has also been decreasing remarkably since this time. The sixth stage is marked by the Hiraiguchi No. 1 kiln in Tokoname City and corresponds to the middle Muromachi period, but from this sixth stage to the seventh stage in the late Muromachi period, the number of kilns became extremely small, and they were mostly concentrated around the Tokoname urban area. Products were mostly limited to jars, pots, and ground bowls, and mountain tea bowls were seen only rarely. Jars and pots also became smaller, and jars in particular became characterized by their wide mouths, with the folds of the mouth rim band tightly fitting the neck of the mouth and a broad chamfer on the top surface. The products of the sixth and seventh stages were fired with oxidizing glaze, and the firing temperature was generally low, giving them a reddish-brown color, with few naturally glazed pieces.
Needless to say, the products of this enormous number of kilns, which numbered more than 1,000, did not meet the needs of the Tokai region alone. The Tokoname kilns, which were the first medieval kilns in Japan, took advantage of their vast clay resources and geographical location to quickly establish a mass production system (division of labor), and captured the market throughout Japan. The distribution of Ko-Jokoname ware is now known to extend from Shichinohe-cho, Kamikita-gun, Aomori Prefecture in the north to Kaimon-cho, Ibusuku-gun, Kagoshima Prefecture in the south, and to the entire Pacific coast of Japan, including Shimane Prefecture and other parts on the Sea of Japan coast. The distribution range is not uniform, however, depending on the type of ware, with bowls and small plates distributed around Ise Bay, three-striped jars distributed from southern Kanto to the Kinai region and parts of Shikoku, and jars distributed throughout Japan, depending on their use and size. Needless to say, the basic type of Ko-Joname ware is miscellaneous daily wares intended for use in medieval farming villages, but there are also many special wares produced for different purposes. One example is a small jar about 30 cm high, which has been excavated from sutra mounds from the Kanto region to the Kinai region as an outer container for sutra cylinders, and another is a three-striped jar that accompanied sutra mounds. There are also many examples of large and small jars used as bone implements.
There are more than a dozen known examples of kawara (roof tiles) produced at the Yamachawan kilns located in the northern and central parts of the Chita Peninsula. Some of them, such as the Yoshida No. 12 kiln in Obu City and the Shayama Kogama kiln in Chita Town, are known to have been used at Anrakujuin in the Toba Detached Palace in Kyoto, providing interesting facts in pursuit of the state of ceramic production at that time.
Atsumi
It was not until the late 1960s that the Atsumi Peninsula Old Kiln Site Group came to be recognized as a major group of medieval old kiln sites in the Tokai region, along with the Seto and Tokoname kilns. However, the existence of the Atsumi Kilns became known surprisingly early, with the discovery of the ruins of a kiln that fired tiles for the reconstruction of the Great Buddha Hall of Todaiji Temple in Irago in 1918, and the ruins of the Hyakudai Kiln in Rokuren, Tahara-cho designated as a historic site in 1922. In addition, the Atsumi County Magazine published in 1923 describes in detail an enormous number of old kiln sites throughout the peninsula. The Atsumi Kiln, which had long been forgotten, came to be noticed again, partly because of excavation surveys conducted in conjunction with the construction of the Toyokawa water supply, and partly because a jar with a lotus petal design, the firing place of which was previously unknown, was confirmed to be the product of the Kajitsubozawa kiln by Suzuki Yukiro and others in 1963, and a series of jars with carved designs were found to have been produced by the Atsumi Kiln. This led to a request for a reexamination of the Atsumi kiln as a production site for a series of jars with engraved designs. Subsequently, until today, the entire peninsula has been investigated by local researchers led by Katsuichi Onoda, and the entire picture of the Atsumi Kiln has become almost completely known.
The Atsumi Kiln extends from the southwestern part of Toyohashi City at the base of the peninsula to Tahara Town, Akabane Town, and Atsumi Town, and the existence of nearly 400 old kiln sites in 74 groups has been confirmed up to now. If we take into account those that have already been destroyed and those that will be discovered in the future, the number of kiln sites will exceed 500. In terms of the number of old kiln sites, this is the fourth largest group of medieval kiln sites in Japan after Tokoname, Sanage, and Seto. These seventy-four groups of old kiln sites vary in size from three or four small ones to more than twenty large ones, but most of them have five to eight kilns per group. These groups of old kiln sites are not uniformly distributed over the entire peninsula, but rather are grouped together in four major areas. In the east, there are 23 groups of 112 kilns from the south bank of the Umeda River to the Shioda River basin in Toyohashi City, 35 groups of 188 kilns from the Shio and Clam River basins in Tahara Town to the Kobe area facing the Pacific coast, 13 groups of 74 kilns from the Ashigaike area in Tahara Town to Akabane Town, and 3 groups of 14 kilns in the Irago area of Atsumi Town. Each of these four areas has a different origin, and each is considered to have developed in its own unique way.
The products of the Atsumi kilns are basically the same as those of the Tokoname kilns. In other words, the Atsumi kiln fired bowls and plates as tableware, bowls as cooking utensils, bottles, jars, and pots as storage containers, as well as ritual utensils, fishing tools, and roof tiles, but the main products were two types of sets: jars, pots, and mortar, and bowls and plates. The bowl and plate kilns cover the entire peninsula, while the jar and pot kilns tend to be concentrated in two groups in the central part of the peninsula. The shapes of these vessels are identical to those found in Tokoname. Ritual implements, which show the difference between the two, will be discussed later in the section on special wares.
The techniques used in the Atsumi kiln are basically the same as those used in the Tokoname kiln, with the exception of the firing technique, which is different due to the nature of the clay. The Atsumi Kiln is located on a low hill facing the Pacific coast in the southern half of the country (see distribution map on page 92), as is known from its distribution, and this low hill is covered by a Pleistocene silt layer called the Atsumi Formation. The clay in this silt layer was used, but it is rich in sand and has low refractoriness. As in Tokoname, wheel-thrown molding with water grinding was used in the early stages of the pottery, but the basic molding method is wheel-thrown molding with a cord. The joints of the wheel-formed potter’s wheel are marked by a stamp made by beating from the outer surface, which is found not only on large pots but also on medium-sized pots. It is noteworthy that the Atsumi kiln retained the ash glaze that had been used since the previous age much longer than the Tokoname kiln. The kiln used for firing was a cellar kiln with a dividing pillar at the boundary between the firing chamber and the combustion chamber, which is unique to the Tokai region. Therefore, the structure is basically the same as that of the Tokoname kiln, but in the Atsumi kiln, the floor of the combustion chamber is deeply inclined toward the inside, and is one step lower at the border with the firing chamber. Therefore, the slope of the firing chamber is steep, and the ceiling is very high. Therefore, the volume inside the kiln is considerably larger than that of Tokoname, and a huge amount of fuel is required to raise the temperature to a certain level. The reason why such a kiln structure had to be adopted was due to the nature of the clay used. Indirect firing was used to avoid damage from direct firing, and smoked reduction firing was used to tighten the firing. This is the reason why many of Atsumi’s works are called “black pots,” with the surface darkened by carbon adsorption. When and how did the Atsumi kiln originate? The bowl and dish kilns have wide firing chambers with steep slopes, while the jar and pot kilns are narrower, longer, and constructed with somewhat more gradual slopes. It has already been pointed out that the mother of the Atsumi kilns was the Ichiriyama kiln site group, a group of Sue ware kiln sites formed in the Nara period in the southeast of Toyohashi City, and the Futagawa Oiwayama kiln site group, which fired Heian ash glazed pottery, which moved northwest from there. Atsumi Kiln is not. The Atsumi kilns are now known to have undergone three stages of transition from the late Heian to the late Kamakura period, and the content and process of change in each stage is similar to that of Tokoname. The first stage belongs to the late Heian period, and the kilns of this first stage are mainly concentrated in two locations, at the foot of Mt. Among these, the kiln that can be dated to the middle of the 12th century is the Oarako kiln at the southwest of Ashigaike, from which many jar shards with inscriptions by Fujiwara no Kencho, who was a provincial governor of Mikawa in the late Heian period, and others were recovered. A group of Osawashita kiln sites at the foot of Mt. An earlier date is given by an outer sutra case inscribed 1121 (Bunsei 2), excavated from Kumano Hongu, Wakayama Prefecture, in Bunsei 8. There is no doubt that this outer vessel was produced by the Atsumi kiln, as it bears the inscription “Hakusai-jishi-bako” (white porcelain box), which is seen on vessels from the Atsumi kiln. Therefore, it is known that production had already begun around the beginning of the 12th century. As mentioned above, Atsumi kilns started from two groups in the central part of the peninsula and gradually spread to the south, and the group entering the Toyohashi City area in the east was formed in the second stage, that is, spreading from the west around the beginning of the Kamakura period. Although it is not clear why the pottery production started in the central part of the peninsula, the Shio-gawa river basin at the foot of Mt. Zao has strong ties to the Ise Jingu Shrine, and the shrine territories such as Kobe and Mikuriya-Misono are widely spread, indicating that ceramic production in this area may have been established as part of the shrine economy. In contrast, there is no Jingu territory in the Ashigaike area, and the fact that pots with the name of the provincial governor on them were made suggests the possibility that these were official kilns of the national government. This inference requires a great deal of evidence, but for now, I would like to present it only as a matter of interest.
Atsumigama products are widely distributed from Iwate Prefecture in the north to Ehime Prefecture in the south, but their distribution range is narrower than that of Tokoname. The main distribution area is limited to the Pacific coast from southern Kanto to the Ise and Kumano regions. Although its occurrence is almost the same as that of Tokoname kilns, the narrower distribution area is probably due to the difference in securing the market since the ash-glazed ceramics of the previous generation. As mentioned earlier, Atsumi kiln products are mainly everyday containers for farmers, such as jars, pots, bowls, and plates, but they also produced a large number of jars with engraved designs as special items, such as the three-jar jars produced in Tokoname. There are two types of jars, large and small, made of half-cut bamboo tubes and decorated with geometric patterns such as ren-arak, lotus petals, and kesa-dasuki. The large ones were often used as outer containers for sutra casks, while the smaller ones were used as bone implements or accompanying objects for sutra mounds. Of particular note among ceramics of the three-stripe pattern is the abundance of ceramics with carved designs depicting the four seasons in the Yamato-e style, such as the jar with autumn grass design (Figure 79). Another specialty is the special sutra tube outer container. There are a variety of forms, but it is known that the oldest type was copied from a sutra case made by the Koshu kilns and gradually changed to a simple cylindrical shape. These are mainly found in sutra mounds in the Ise-Kumano region. There are also special large wares with floral designs engraved in intaglio, such as those excavated from Hanabusa Sutra Mounds in Kyoto Prefecture.
While the Tokoname kilns have maintained continuous production to this day, the Atsumi kilns ceased to exist before the end of the Kamakura period (1185-1333). Some people think that the reason for this is related to the Jingu economy, but considering that the closure of the Atsumi kilns occurred at about the same time across the entire peninsula, it is more likely that it was due to the uneconomical firing techniques of the Tokoname kilns, which resulted from the nature of the clay, and that the Atsumi kilns lost the production competition with the Tokoname kilns. The reason is that they lost the production competition with the Tokoname kilns.
Sanage
The Sanage kiln, which had been the center of ash glaze pottery production since the Heian period (794-1185), was broken down into three separate kilns around the beginning of the 12th century, giving rise to Seto in the north and Tokoname in the south. Here, we will discuss the subsequent development of the Sanage kiln, which was the center of Heian ash-glaze pottery production. As already mentioned, Seto was the center of high-end ash-glazed and iron-glazed pottery production, while Tokoname produced large jars and other miscellaneous daily wares. Underlying this regional division of labor was the widespread production of daily tableware, mainly bowls and plates, which had been around since the Heian period (794-1185). The Sanage kiln survived as a ceramic production center for such bowls and plates. Bowls that have lost their ash glaze and are crudely made are generally called mountain tea bowls in the Tokai region. These mountain tea bowls are used in sets with small plates, which is a continuation of the tradition of using a set of large and small bowls as tableware in the late Heian period, and in the Kamakura period, small bowls lost their bases and became small plates.
The medieval sancha-bowl kilns at the Sanage Kiln spread over a wider area than the distribution area of ash-glazed ceramics of the previous period, and since the remains of 560 old kilns have been confirmed in the old period area, it is estimated that there are over 800 kilns in the entire area, including those that have been destroyed. Needless to say, the products of these mountain tea bowl kilns were mainly tableware such as bowls and plates, but in the early stages, wide-mouthed bottles and large short-necked jars were also fired, which were descended from the previous generation. At this stage, the traditional suribachi, a deep-bottomed bowl with a thick base, was replaced by a large flat bowl with an elevated base, which was fired along with bowls and plates at each kiln. In the Higashiyama district on the western edge of the city, there are several kilns known to have fired various types of Buddhist ritual vessels, roof tiles, and four-eared jars, and the contents are not uniform. In particular, the fact that many types of vessels were fired in the Higashiyama area, which is not found elsewhere, indicates the special position of this area among the Sanage kilns. The center of ash-glazed pottery production in the previous period was in the Kurozasa district in the east, and kilns in the mid-9th to early-10th centuries produced excellent ash-glazed pottery and ceramics with floral motifs, as well as large bowls inscribed “uchi “竪所”, which suggest that they were official kilns of the national government. However, when the kiln was transformed into a mountain tea bowl kiln, it became a simple production of bowls, plates, and bowls only. In contrast, the fact that many products other than bowls, plates, and bowls were fired in the Higashiyama district, which was a subsidiary kiln in the previous generation, indicates that the character of the kiln as a government kiln shifted from the Kurozasa district to this district. The fact that a bowl with the name “Koseisho” excavated from the side of the Gonakayama burial mound in Mizuho Ward, Nagoya, was made by the Higashiyama kiln, is also strong evidence of this. As mentioned in the previous section on Seto, there are several known kilns in the Higashiyama area that fired four-mimi jars imitating Song dynasty (960-1279) porcelain, and the Higashiyama Kiln No. 105 is known to have responded sensitively to the trends of the times with new decorative designs on its vessel surfaces that imitate Chinese ceramics. The “Kannon” is a very important example of the “Kannon” in the history of Japan. The same is true of the production of various types of Buddhist ritual vessels and roof tiles, which were closely connected with the central government and local shrine and temple forces. Eventually, the center of pottery production for the upper class shifted to Seto in response to the demands of the times, and after the establishment of Kosedo, the Higashiyama kilns were almost completely abandoned. The situation was the same in the Sanage Kiln area in the east, and it is thought to have completely disappeared by the end of the Kamakura period.
What then is the situation of medieval ceramic production in the Tokai region other than Owari-Mikawa? First, let us look at Mino. The center of ceramic production in Mino is the Minosue kiln, which is located in the northern part of the Kiso River and extends over the low hills from Kakamigahara City to Gifu City. More than 130 Sue ware and 瓷器 kilns have been discovered here, of which about 20 are 瓷器 kilns. After the Sue ware kilns ceased to exist, these 瓷器 and ash glaze kilns were revived as kiln production sites in the 10th century under the influence of the Onokita and Sanage kilns, but by the 12th century, they had not transformed into widespread mountain tea bowl kilns as in other areas, and only a few of them barely maintained production.
However, it has recently become clear that some of them, such as one ancient kiln behind Mt. Inada, fired unglazed four-mimi jars of the same shape as those of Kosedo, and it is known that they were in operation until around the middle of the Kamakura period. However, the center of Mino ceramic production in the Middle Ages was in the Tono region, including Tajimi and Toki cities, where various forms of pottery production were seen. Among them, a series of kilns that fired Kosedo-style glazed ceramics and sanchawan (mountain bowl) kilns that were descended from ash-glazed ceramics have already been mentioned in the section on Seto Mino, but in recent years, an enormous number of sanchawan kilns have been excavated in connection with development, and the aspect of the succession to large kilns that began in the late 15th century is becoming clear.
One of the recently discovered medieval kilns in Tono is the Kaneyama Kiln Site Group. The Kaneyama kilns are a group of medieval kiln sites built in various valleys on the hills facing the Kiso River in Kaneyama-cho, Kani County. Of these, only Koshiyama Kiln No. 1 has been excavated, so the full picture is not yet clear, but it is noteworthy in that it fired mainly jars and pots similar to those found in Tokoname. There are very few mountain bowls, small plates, and bowls. Jars and pots are so similar in form and color tone to those of Tokoname that it is difficult to distinguish them at first glance. However, the difference between the two is that the clay used is highly refractory, fired at a higher temperature and harder than that of Tokoname, and the folded edge of the mouth band is not as wide as that of Tokoname. The uniqueness of the Kaneyama kiln in the mountain tea bowl area of Tono is thought to be an indication of the region’s ability to meet the demand for large jars and pots that took advantage of the water transportation of the Kisogawa River.
Another medieval kiln that has become newly known in the Tono area since the end of World War II is the Nakatsugawa Kiln Site Group. A large scale excavation survey of these kiln sites was conducted in 1958 by a research team led by Fujio Koyama, and the details of the excavation are known to some extent. The kilns are located in the western part of Nakatsugawa City, extending long east to west across the hills between the Chuo Line and the Kiso River, and partly to the south. Twenty-five old kiln sites have been confirmed, but the actual number is probably double this number. All of these kilns have the structure of the mountain tea bowl kilns common in the Tokai region, and there are three types of products: those that mainly produce mountain tea bowls and small plates, those that mainly produce jars, pots, and mortar, and those that produce a mixture of both. The mountain tea bowls and small plates are the same as those found in the Tokai region, and the jars, pots, and mortar are the same as those found in the Tokoname kiln. The Nakatsugawa ware is extremely hard, with an almost white base, and a large number of beautiful pieces of pottery with a light green natural glaze have been excavated. The Nakatsugawa ware as complete wares is still not well known. The mother kilns of this kiln were ash glazed pottery kilns that spread throughout the Tono region in the late Heian period, and one branch of these kilns is the Koishizuka kiln in Chidanbayashi, Nakatsugawa City. These ash-glazed pottery kilns all shifted to the production of miscellaneous vessels, mainly mountain tea bowls and small plates, similar to the Sanage kilns in the 12th century, but there is a reason why jars and pots were widely produced in the Nakatsugawa kiln sites. The widespread development of ash-glazed pottery kilns in the Tono area was in response to the demand for ash-glazed pottery in the eastern part of Japan. The Nakatsugawa kiln, located at the easternmost tip of the region, produced large jars and pots because of its geographical advantage of being close to the east. The Nakatsugawa kiln is thought to have started out as a Koishizuka kiln at the end of the Heian period, transformed into a mountain tea bowl kiln, and began producing jars and pots under the influence of Tokoname in the Kamakura period. Initially, they were fired together with bowls and plates, but eventually, from the end of the Kamakura period to the Nanbokucho period, they were divided into two types of kilns: bowl and plate kilns and jar and pot kilns. Needless to say, this division of labor was due to the increase in demand. However, the kilns ceased to exist at the beginning of the Muromachi period (1333-1573), without maintaining production. The reason for this is not clear, but it is thought that it was difficult to maintain the production of only jars and pots, as the Atsumi Kiln and other mountain tea bowl kilns in the Tokai region had also ceased to exist.
In addition to the above, other medieval ceramic sites in the Tokai region include the ruins of ancient kilns in the Toe area. Like Owari and Mino, they are also a group of mountain tea bowl kiln sites that were based on the production of ash-glazed pottery, mainly bowls and plates, but also some jars and bottles.
