A district (郡; gun) was the administrative unit during the period from 1890 to 1923, which is roughly equivalent to the county of the United States, and was ranked at the level below prefecture and above city, town or village.
It is still used in the Japanese addressing system to identify the location of towns or villages. Cities, unlike counties in the US, belong directly to prefectures.
Confusing cases in Hokkaido
Becase district names had been unique in the province and nowadays prefecture boundaries are roughly aligned to province boundaries, most district names are unique in the prefecture. However, the Hokkaido Prefecture, consisting of eleven provinces, involves a few confusing cases.
There are three Kamikawa Districts and two Nakagawa Districts in the Hokkaido Prefecture.
Abuta District, Rumoi District, Sorachi District, and Yufutsu District are deceptively similar, but each of them is a single district allotted to two subprefectures.
See also: Geography of Japan
