The electoral map was reformed in 1944 which was used in the upcoming election later that year.

The maps of Japan and Bingo Province were reformed in the 1870s.

The maps of Japan including Hidaka Province were reformed in the 1870s.

The electoral map was reformed in 1930 and was first served in the 1931 elections.

The electoral map was reformed in 1890 just a few months prior to the elections later that year.

The electoral map was reformed in 1939 just prior to the elections later that year.

The electoral map was reformed in 1922 prior to the elections that were held in the following year.