Sizing up the forthcoming Upper House election

This month, the Japanese public will be going to the ballot boxes to vote for members of Japan’s Upper House.

In the past, these elections have been moderately important — and far less so compared to Lower House votes. However, based on the current state of politics in Tokyo, this is the most consequential Upper House election since 2007, when the outcome catalyzed the toppling of the Liberal Democratic Party-led government.

The stakes in this election are equally as high as they were back then. Prime Minister Shigeru Ishiba needs a win to secure longer-term viability as the country’s leader. The ruling coalition is already struggling with a minority government and stands to lose even more legislative power in this vote. As for the opposition parties, this election is a battle to do something they have long been unable to do: position themselves as the standout alternative to the LDP. They all now have less than three weeks to win over the Japanese public.

Upper House elections are fundamentally different from Lower House votes in terms of the number of seats and regularity. The Upper House is composed of 248 seats with lawmakers serving six-year terms. Unlike the Lower House, which can be dissolved by the prime minister or via a no-confidence motion, Upper House elections are held every three years, with only half the seats up for a vote to preserve stability in governance. In other words, for the forthcoming election, only 124 of the 248 seats are up for grabs.

Based on their constitutionally mandated authorities, the Upper House is the weaker of the two houses in the Japanese Parliament. The Lower House has the ability to overrule decisions from the Upper House, it proposes the budget and every prime minister since the promulgation of the constitution has been a Lower House politician.

Because of this, Upper House elections have always been about one thing: securing a simple majority. The goal for the ruling coalition is to preserve that majority rule so that whatever bills make it through the Lower House can be rubber stamped in the Upper House. The goal for the opposition is to win the Upper House majority to disrupt the legislative efforts of the ruling coalition. This means that the Upper House can frustrate lawmaking by voting against Lower House-passed bills and forcing the ruling coalition to cobble together a two-thirds vote to overturn the Upper House decision.

The opposition winning a majority in the Upper House can be a death knell for the ruling coalition, as evidenced in the late 2000s. In 2007, the Democratic Party of Japan won the majority in the Upper House, handing them an essential tool for disrupting the ruling coalition’s legislative designs. The LDP-led government had already been on the decline and the inability to achieve meaningful progress in the Parliament — particularly after the Lehman Shock in 2008 — expedited the public’s declining confidence in the party’s ability to lead Japan. By the next Lower House election in 2009, the LDP lost total control to the opposition for the first time since 1993.

Understanding this, one of the implied tasks for Lower House lawmakers is that they must stump for Upper House politicians. After all, if they want their legislative priorities realized, they need help from their Upper House counterparts. So, while this is a vote for only 124 seats out of the total 713 in the two houses of Parliament, it is an “all-hands-on-deck” situation.

This is even more so in the forthcoming election than previous Upper House votes. The current situation has forced the LDP into negotiations and consultations with opposition parties unlike anything it has experienced before. Meanwhile, public faith in Ishiba’s government and the LDP remains relatively low. The only saving grace for the LDP is that public approval has not yet found a home in a single opposition party. Major political competitors will seek to change that with this forthcoming election.

For Ishiba, this election will seal his fate as the leader of the LDP and prime minister of Japan. He is already a polarizing figure inside the LDP and there are others like former economic security minister Sanae Takaichi vying to succeed him. While the LDP was willing to privilege stability under Ishiba despite his inability to excite the Japanese public ahead of the last snap election, consecutive campaign failures would provide an opportunity for intraparty opponents to make political moves.

The bar for Ishiba remains the same as any Upper House election: ensure the LDP-Komeito coalition maintains the majority. He has already enjoyed a bump in the polls owing to progress on the highly visible issue of rice prices in Japan, but he will spend the next few weeks avoiding any contentious topics. This includes things such as tariff negotiations and defense spending discussions with the United States, which are political landmines for the prime minister. Instead, observers should expect Ishiba to put his full weight behind policy measures aimed at relieving economic pressure on individual households.

The ruling coalition will throw its full weight behind campaign efforts because they cannot afford to lose any more legislative power. The coalition has been in a downward spiral with regard to voter confidence. The public handed the LDP and junior partner Komeito a defeat in the October 2024 Lower House election owing to waning confidence in their ability to lead the government.

The negotiation requirements inherent to a minority government have only further disrupted the coalition’s ability to implement its policy and lawmaking priorities, which may negatively impact the coalition’s chances of success in the forthcoming vote. Losing the Upper House would only frustrate its efforts further, contributing to even less voter confidence that may be just what the opposition needs to wrest control.

To break this cycle, the LDP and Komeito will need to go beyond their traditional power bases. While both parties maintain large vote-getting apparatuses throughout the country, they must find new ways to appeal to nontraditional support blocs. The focus on alleviating economic burdens versus global geopolitical issues will help, but there is still a question of how the LDP and Komeito will modernize their engagement with voters via social media and in their messaging efforts.

Meanwhile, the opposition parties must use this election to stand out from the pack. Despite the LDP’s negative trends in public approval over the past few years, opposition parties have neither coalesced as a viable coalition nor stood out as individual challengers. Continued failure to seize these political opportunities may well give the LDP the space needed to correct its internal policy challenges and regain just enough voter confidence to start reversing its public image.

The two conventional contenders in the forthcoming race are the Constitutional Democratic Party of Japan and the Democratic Party for the People. The CDP has returned to its DPJ roots by leaning on former Prime Minister Yoshihiko Noda’s leadership as an alternative to LDP-led rule. Meanwhile, the DPP has doubled down on Yuichiro Tamaki despite his widely publicized extramarital affair, which sidelined him briefly between 2024 and 2025. It is betting that his centrist approach and willingness to work across the aisle in Parliament can lift it beyond fringe status — a party that has stayed relevant mainly by exploiting the LDP’s weakness as a minority government. Neither the CDP nor the DPP has figured out yet how to excite broad masses of Japanese voters, but they will be scrambling during the next three weeks to do so.

As for unconventional contenders, the right-wing populist party Sanseito is drumming up unexpected support. Coming off a surprising showing in the Tokyo municipal elections, Sanseito is heavily leveraging social media to continue its momentum through the Upper House race. This new group of prospective lawmakers is counting on their promise of “Japan First” policies to peel conservative voters away from the mainstream parties. Of course, this would not be the first time a new party roars onto the political scene only to fizzle out after poor showings at national-level elections, so Sanseito will be fighting hard to avoid that outcome.

Given all these circumstances, this is shaping up to be one of the most unusual Upper House elections in decades. With stakes at play, it will certainly be one of the most impactful.