Haji pottery (土師器)
Haji pottery is a type of earthenware that evolved from Yayoi-type pottery and was produced from the Kofun (tumulus) to Nara and Heian periods, until replaced by Kawarake earthenware in the medieval and early modern times. The pottery was made in the same age as Sue pottery (unglazed earthenware) but was inferior in quality to Sue pottery. Haniwa is also Haji pottery.
Although made mostly as pots and other storage containers, it was also used as bowls, plates and other wares used in making offerings to divinities until the mid-ninth century. For cooking rice, the "koshiki" was used.
The pottery is not airtight and is made by firing with oxidizing flame in a small pottery oven dug on the ground. For this reason, firing occurs at 600 to 750 degrees, lower than for Sue pottery, creating pottery that is either orange or rust-colored and softer than Sue pottery.
Haji was used in place of Yayoi pottery in the Kofun period. Haji has been classified by shape into Shonai type and Furu type (excavated from Furu Site in Tenri City, Nara Prefecture), with the Shonai type regarded the older type of Haji pottery. When Shonai type pottery was still used, there were no large tumuli showing consistency in form. This suggests that Shonai type pottery dates back to the period prior to the age of tumulus construction. In chronological order, Yayoi V type is regarded the oldest, followed by Shonai type and later by Furu type.
Although roughly identical in age as Sue pottery, Haji pottery is an evolved form of Yayoi type pottery and therefore is extremely difficult to determine from which type Haji pottery started. Initially, occurrence with tumuli was regarded its distinctive historical features, but the emphasis today is on nationwide occurrence. In contrast to Jomon and Yayoi types that were strongly regional in characteristic, Haji is found distributed widely from Honshu to Kyushu islands, based on identical design and production method, although some regional traits can also be found if scrutinized closely. This strongly supports the theory that there was dramatic growth of cultural exchange unheard of in the previous age, behind which advances were made in political unification.
From the ninth century, exchange between groups of Haji craftsmen (Hajibe) and Sue craftsmen (Tobe) grew, resulting in the creation of a large volume of earthenware that is midway between the two in terms of design, such as Rokuro-haji and Haji-shitsu pottery.