Abstract
The formation of the Oda District during the Ritsuryô Period is un-documented. We may safely assume, however, that formation took place in the Pre-Taika Period by the aggregation of parts of the two agata of Kibi-Naka and Kawashima to Hokuki which, consequently, became the central part of the Oda District.
Oda is the name of both the whole district and the central part of the district. Many names connected with the Gûke (District Office) have been found in the central part and the Kôri-gongen-gu, which was probably the central shrine for the entire district during the Ritsuryô Period, is still extant.
The so-called Oda Umaya (Oda Relay-station) was probably located in Maido east of Oda. Many roof tiles from the temple which was probably the Gunji (the district temple connected with the Gûke) have also been found in Maido.
Since both Oda, which gave its name to the whole district, and Maido, which is near Oda, show traces of having been centers of the district, we conclude that the Gûke was established in Oda.
The San-yo Road is thought to have passed through the southeastern part of the Gûke area; thus, we can infer that the Gûke had easy access to land transportation. Moreover, since the Gûke was situated on the Oda River, it must have been connected to good water transportation links.
Judging from the fact that three different Jôri systems have been found in the comparatively small Oda valley, it seems certain that the Gûke was established at the time when the Jôri systems were being enacted. As the southern side of the Gûke is 6 cho (about 654 meters) in length, it can be assumed that the Gûke was 6 cho square.
