As of Dec. 31, a total of 253 candidates were set to run in the upper house election this summer, according to Yomiuri Shimbun inquiries.
The 24th House of Councillors election will be the second one held since the Liberal Democratic Party regained control of the government.
Attention is being focused on the ability of the ruling LDP and Komeito coalition to maintain its upper house majority, which would require at least 122 seats including those not up for grabs in the upcoming election. Another point of interest is whether the LDP by itself can gain an upper house majority for the first time in 27 years.
Of the candidates up for election, 72 will run in the proportional representation bloc, in which 48 seats are being contested, and 181 will run in constituencies in which 73 seats are being contested. Candidates are being fielded more quickly compared to the previous upper house election in 2013, which was held just after a House of Representatives election.
Electoral districts key
The Public Offices Election Law was revised for the upper house election this year to reallocate seats, increase seats by 10 over some prefectures and reduce them by 10 over others, bringing the number of constituencies with only a single seat to the highest ever at 32. Results in electoral districts will hold significant sway over the victory or defeat of political parties.
Constituencies with two seats up for grabs fell from 10 to four. In such constituencies in the past, the largest ruling and opposition parties often won a single seat each.
Among the ruling coalition's upper house seats, 76 are not being contested. To maintain a majority, the ruling parties must win 46 seats.
The LDP has decided to endorse candidates in 30 electoral districts with only a single seat up for grabs. To secure more seats, the LDP is planning to field two candidates each in three constituencies where at least three seats are being contested.
The LDP is also aiming to regain its single-party majority, which it lost in the 1989 upper house election after suffering a major setback. Of the LDP's seats, 50 will be contested and 65 will not. The party will have a total of 122 seats if it manages to win 57 more seats.
The LDP will face a lower hurdle if Yoshiyuki Inoue, an upper house member who joined an LDP-led parliamentary group, is included.
Komeito will field fresh faces in the prefectural constituencies of Aichi, Hyogo and Fukuoka, which saw their number of contested seats increased. Komeito will be running seven candidates in constituencies this year, up from four in 2013.
The Democratic Party of Japan is struggling to find individuals who can run as endorsed candidates in single-seat constituencies.
The DPJ has been coordinating to back independent candidates as common candidates for opposition parties, so the party is trying to co-operate with other opposition parties including the Japanese Communist Party and the Japan Innovation Party. The strategy aims to prevent opposition party candidates from working against each another amid a political situation said to be dominated by the LDP.
In the Kumamoto prefectural constituency, the JCP withdrew its candidate because another individual declared the intention to run as an independent. Similar actions are being considered in other electoral districts, including the prefectural constituencies of Yamagata and Ishikawa.
But many independent candidates are presenting policy stances similar to the DPJ. Opposition parties are also at odds over certain policies like security and the economy as well as views regarding the Constitution. Such factors suggest that the ruling parties could criticise co-operation among opposition parties as an illicit union.
In the lower house, the LDP-Komeito coalition holds more than two-thirds of the seats. If the number of seats of upper house lawmakers positive toward constitutional amendments reaches two thirds, or 162, a political situation enabling a proposal to amend the top law could be prepared for the first time under the current Constitution.
Among the upper house seats not up for grabs this year, 88 are held by the LDP, Komeito, Osaka Ishin no Kai (Initiatives from Osaka), Nippon no Kokoro wo Taisetsu ni Suru To (Party for Japanese Kokoro) and independents who are forward-looking about amending the Constitution. These parties need to win at least 74 more seats to achieve the goal of a two-thirds majority.
Lowered voting age
To correct vote-value disparities, two pairs of prefectural constituencies - Tottori and Shimane, and Tokushima and Kochi - were merged for the first time in Japanese constitutional history.
The LDP endorsed incumbent lawmakers who won in Shimane and Tokushima prefectural constituencies in the 2010 election, and chose to have the candidates lined up for Tottori and Kochi prefectures run in the proportional representation bloc instead. The LDP is looking to secure victories in the merged electoral districts by attracting voters under the influence of business organisations.
The law was also revised to lower Japan's voting age to 18, effective starting June 19. If the upper house election is announced on or after that date, about 2.4 million people aged 18 and 19 will become eligible voters starting from the summer election. Political parties have started striving to expand their support base among young people.
Possible voting dates for the upper house election include June 26, July 3, July 10, July 17 and July 24, assuming the current ordinary Diet session is not extended and the voting date will fall on a Sunday. The date needs to be on July 10 or later to take advantage of the lowered voting age.
If the lower house is dissolved, the Constitution stipulates a general election should be implemented within 40 days. If a decision to dissolve the lower house is made on June 1 when the ordinary Diet session ends, the government and ruling parties could hold both the lower house and upper house elections on the same date of July 10. Doing so would mark the first time since 1986 that there were "double elections."