The House of Councillors, the upper house of the Japanese National Diet is made up of 248 members elected from 45 districts plus a national proportional representation list. Until 2015, there were 47 districts which coincided with the 47 prefectures of Japan.
In order to address the imbalance in voter representation between rural and urban voters, the Public Officers Election Law was amended in 2012 and again in 2015. The 2015 amendment merged the two smallest districts, the Tottori and Shimane districts, to create a combined Tottori-Shimane at-large district, and merged the third- and fourth-smallest districts, the Kochi and Tokushima districts, to create a combined Tokushima-Kōchi at-large district. Other changes to the number of Councilors have also been made to address the imbalance. [1] Below is a table of districts, sortable by name, magnitude and voter disparity, based on the official number of registered voters as of September 2015.
District | Registered voters [2] | Magnitude | Disparity | |
---|---|---|---|---|
Pre-reform | Post-reform | |||
Aichi | 5,927,668 | 8 | ||
Akita | 888,496 | 2 | ||
Aomori | 1,122,948 | 2 | ||
Chiba | 5,092,741 | 6 | ||
Ehime | 1,169,427 | 2 | ||
Fukui | 644,447 | 2 | ||
Fukuoka | 4,135,977 | 6 | ||
Fukushima | 1,607,908 | 2 | ||
Gifu | 1,666,610 | 2 | ||
Gunma | 1,616,400 | 2 | ||
Hiroshima | 2,313,131 | 4 | ||
Hokkaido | 4,537,448 | 6 | ||
Hyogo | 4,536,912 | 6 | ||
Ibaraki | 2,411,307 | 4 | ||
Ishikawa | 939,531 | 2 | ||
Iwate | 1,074,018 | 2 | ||
Kagawa | 818,470 | 2 | ||
Kagoshima | 1,371,073 | 2 | ||
Kanagawa | 7,421,431 | 8 | ||
Kumamoto | 1,473,659 | 2 | ||
Kyoto | 2,088,383 | 4 | ||
Mie | 1,489,396 | 2 | ||
Miyagi | 1,907,518 | 2 | ||
Miyazaki | 918,533 | 2 | ||
Nagano | 1,737,214 | 2 | ||
Nagasaki | 1,148,570 | 2 | ||
Nara | 1,140,129 | 2 | ||
Niigata | 1,925,565 | 2 | ||
Ōita | 972,380 | 2 | ||
Okayama | 1,566,428 | 2 | ||
Okinawa | 1,115,392 | 2 | ||
Osaka | 7,140,578 | 8 | ||
Saga | 679,289 | 2 | ||
Saitama | 5,933,788 | 8 | ||
Shiga | 1,121,066 | 2 | ||
Shizuoka | 3,052,579 | 4 | ||
Tochigi | 1,621,930 | 2 | ||
Tokushima-Kochi | 1,261,100 | 2 | ||
Tokyo | 10,947,527 | 12 | ||
Tottori-Shimane | 1,051,880 | 2 | ||
Toyama | 888,832 | 2 | ||
Wakayama | 825,373 | 2 | ||
Yamagata | 937,920 | 2 | ||
Yamaguchi | 1,173,848 | 2 | ||
Yamanashi | 692,001 | 2 | ||
Total | 104,106,821 | 148 |
In addition to the smaller districts mentioned above, the House of Councillors also has a single block for the entire nation. It elects 50 members per election (100 in total) based on the D'Hondt method.
Tokushima at-large district was a constituency of the House of Councillors in the Diet of Japan. It consists of Tokushima Prefecture and elects two Councillors, one every three years by a first-past-the-post system for a six-year term. In the first election in 1947, Tokushima like all districts used single non-transferable vote to elect both its Councillors in one election.
Tottori 1st district is a constituency of the House of Representatives in the Diet of Japan. It covers roughly the Eastern half of Tottori and consists of the cities of Tottori and Kurayoshi and the districts of Iwami, Yazu and the town of Misasa in Tōhaku District. In 2012, 256,020 eligible voters were registered in the district. In 2013 the town of Yurihama was transferred to the 2nd district. Before the 2021 elections, the district had 230,959 eligible voters, fewer than in any other single member electoral district.
Saitama at-large district is a three-member constituency of the House of Councillors, the upper house of the national Diet of Japan. It consists of Saitama and elects three Councillors for six-year terms every three years by single non-transferable vote.
The Hyogo at-large district is a constituency that represents Hyogo Prefecture in the House of Councillors in the Diet of Japan. It currently has five Councillors in the 242-member house, but this representation will increase to six by July 2019.
The Tottori at-large district was a constituency that represents Tottori Prefecture in the House of Councillors in the Diet of Japan. Councillors are elected to the house by single non-transferable vote (SNTV) for six-year terms. Since the establishment of the current House of Councillors electoral system in 1947, the district has elected two Councillors, one each at elections held every three years. With its 474,963 registered voters it is the smallest electoral district for the house. Accordingly, a 2015 revision of the Public Officers Election Law will see the district merged with the Shimane At-large district to create the Tottori-Shimane At-large district; this change took effect at the 2016 election, at which one Councillor was elected.
The Shimane at-large district was a constituency that represents Shimane Prefecture in the House of Councillors in the Diet of Japan. Councillors are elected to the house by single non-transferable vote (SNTV) for six-year terms. Since the establishment of the current House of Councillors electoral system in 1947, the district has elected two Councillors, one each at elections held every three years. With its 576,297 registered voters it is the second-smallest electoral district for the house. Accordingly, a 2015 revision of the Public Officers Election Law will see the district merged with the Tottori At-large district to create the Tottori-Shimane At-large district; this change will begin to take effect at the 2016 election, at which one Councillor will be elected.
The Kochi at-large district was a constituency that represents Kōchi Prefecture in the House of Councillors in the Diet of Japan. Councillors are elected to the house by single non-transferable vote (SNTV) for six-year terms. Since the establishment of the current House of Councillors electoral system in 1947, the district has elected two Councillors, one each at elections held every three years. With its 618,834 registered voters it is the third-smallest electoral district for the house. To address the imbalance in representation between districts, a 2015 revision of the Public Officers Election Law will see the district merged with the Tokushima At-large district to create the Tokushima-Kochi At-large district; this change will begin to take effect at the 2016 election, at which one Councillor will be elected.
The Tokushima-Kochi at-large district is a constituency of the House of Councillors in the Diet of Japan. The district was formed in 2015 from a merger of the Tokushima and Kōchi at-large districts. Liberal Democratic Party member Yusuke Nakanishi was elected as its first representative at the House of Councillors election in July 2016.
The Tottori-Shimane at-large district is a constituency of the House of Councillors in the Diet of Japan. It was formed pursuant to a 2015 revision of the Public Officers Election Law from a merger of the Tottori and Shimane at-large districts, the two smallest districts in the country, to address the imbalance in representation between rural and urban voters. The district has 1,068,348 registered voters and was contested for the first time at the House of Councillors election that was held on 10 July 2016.
The Aomori at-large district is a constituency that represents Aomori Prefecture in the House of Councillors in the Diet of Japan. Councillors are elected to the house by single non-transferable vote (SNTV) for six-year terms. Since the establishment of the current House of Councillors electoral system in 1947, the district has elected two Councillors, one each at elections held every three years. It has 1,122,948 registered voters as of September 2015.
The Osaka at-large district is a constituency of the House of Councillors that elects Councillors to represent Osaka Prefecture in the National Diet of Japan. From 1947 the district has elected three Councillors every three years by single non-transferable vote for six-year terms, such that there are six Councillors representing the district in the 242-member house. A revision to the Public Officers Electoral Law in 2012 increased the district's representation so that four Councillors were elected at the July 2013 election which will give the district a total eight Councillors by 2019.
Ehime at-large district is a constituency of the House of Councillors in the Diet of Japan. It represents Ehime Prefecture and elects two Councillors, one every three years by a first-past-the-post system for a six-year term. In the first election in 1947, Ehime like all districts used single non-transferable vote to elect both its Councillors in one election. It has 1,169,427 registered voters as of September 2015. As a predominantly rural district, it has favoured the Liberal Democratic Party (LDP) candidate in most elections.
The Yamagata at-large district is a constituency that represents Yamagata Prefecture in the House of Councillors in the Diet of Japan. Councillors are elected to the house by single non-transferable vote (SNTV) for six-year terms. Since the establishment of the current House of Councillors electoral system in 1947, the district has elected two Councillors, one each at elections held every three years. It has 937,920 registered voters as of September 2015.
Saga at-large district is a constituency that represents Saga Prefecture in the House of Councillors in the Diet of Japan. Councillors are elected to the house by single non-transferable vote (SNTV) for six-year terms. Since the establishment of the current House of Councillors electoral system in 1947, the district has elected two Councillors, one each at elections held every three years. It has 679,289 registered voters as of September 2015.
The Fukushima at-large district is a constituency that represents Fukushima Prefecture in the House of Councillors in the Diet of Japan. It currently has three Councillors in the 242-member house.
The Gifu at-large district is a constituency that represents Gifu Prefecture in the House of Councillors in the Diet of Japan. It currently has three Councillors in the 242-member house.
The Niigata at-large district is a constituency that represents Niigata Prefecture in the House of Councillors in the Diet of Japan. Since July 2019, it has two Councillors in the 242-member house, a decrease from its previous contingent of 3.
The Yamanashi at-large district is a constituency that represents Yamanashi Prefecture in the House of Councillors in the Diet of Japan. It has two Councillors in the 242-member house.
The Fukui at-large district is a constituency that represents Fukui Prefecture in the House of Councillors in the Diet of Japan. It has two Councillors in the 248-member house.
Kazuhiko Aoki is a Japanese politician. After an earlier career working for a television broadcasting company, he entered the field of politics, serving as secretary to his politician father Mikio Aoki since 1999. In 2010 he succeeded his father as a member in the House of Councillors for the Shimane at-large district. A member of the Liberal Democratic Party, Aoki was re-elected to the House in July 2016 as the member for the merged Tottori-Shimane at-large district. He is affiliated to the revisionist lobby Nippon Kaigi.