The Surge of Emerging Conservative Forces In Japan’s 2025 Senate Election

This policy brief examines the rise of the Sanseito and the Japan Conservative Party in the July 2025 Japanese Senate elections, through three key lenses: (1) public discontent with the LDP and the fragmentation of the conservative base, (2) external factors driving nationalist sentiment amid a deteriorating security environment, and (3) internal factors, including economic stagnation and rising anti-foreigner sentiment. By analyzing these dynamics, we aim to illuminate the broader political and social implications of this electoral shift.

 

Contents

• Disillusionment with the LDP and the rise of new conservatism
• A worsening security environment and rising nationalism
• Economic stagnation and rising xenophobia
• Economic stagnation and rising xenophobia
• Policy Recommendations:
  Responding to the rise of new conservative forces and ensuring Japan’s political stability
• Conclusion

The July 2025 Japanese Senate election marked a pivotal moment in the nation’s political landscape, as emerging conservative parties, notably the Sanseito and the Japan Conservative Party, achieved an unexpected surge in support. In the election, the Liberal Democratic Party (LDP) won 39 out of its 52 contested seats, losing 13 seats. Meanwhile, Sanseito made significant gains, increasing its representation from one seat to 14. The 1300% increase in seats (from 1 to 14) by the Sanseito in the 2025 House of Councillors election is an extremely rare and unprecedented case in the history of Japanese upper house elections. Historically, there have been instances of significant seat increases, such as the Democratic Party for the People in 2019 (from 4 to 6 seats, a 50% increase) and the Japan Innovation Party in 2013 (from 2 to 8 seats, a 300% increase), but no record exists of a surge as dramatic as that of the Sanseito.

The newly formed Japan Conservative Party also entered the national stage by winning two seats. These new conservative forces have capitalized on a growing sense of disillusionment with the political status quo, tapping into nationalist sentiments and widespread frustration with economic stagnation.

The future of Japanese politics is uncertain, but if a new conservatism that distances itself from the Liberal Democratic Party (LDP) gains influence in the political arena, it could lead to further multipolarization and fragmentation within Japanese politics. Phenomena like the Ishiba administration, where the ruling party acts as a de facto opposition, may become even more prevalent. Additionally, if this new conservatism expands its influence, Japan’s moderate diplomatic stance could be undermined, potentially leading to a scenario where Japan adopts a proactively tough posture toward China and South Korea.

House of Councillors, one of the two chambers of Japan’s National Diet, plays a vital role alongside the House of Representatives in the legislative branch. Its primary functions include deliberating and enacting laws, approving budgets, ratifying treaties, and nominating the prime minister. Unlike the House of Representatives, the House of Councillors is expected to serve as a ‘chamber of reconsideration’, conducting more deliberate reviews. With a six-year term (half elected every three years) and no dissolution, it ensures continuity. While the House of Representatives holds precedence in areas like budget approval and prime minister nomination, where the House of Councillors’ decisions are less final, the consent of both chambers is required for legislation, providing a check from diverse perspectives. Its electoral system, combining nationwide proportional representation and prefectural constituencies, reflects regional and varied opinions. This structure helps moderate rapid policy shifts driven by the House of Representatives’ majority, contributing to stable governance. The next House of Councillors election is scheduled to take place around July 2028.

This article examines the rise of these parties through three key lenses: (1) public discontent with the LDP and the fragmentation of the conservative base, (2) external factors driving nationalist sentiment amid a deteriorating security environment, and (3) internal factors, including economic stagnation and rising anti- foreigner sentiment. By analyzing these dynamics, we aim to illuminate the broader political and social implications of this electoral shift.

Disillusionment with the LDP and the rise of new conservatism

For decades, the Liberal Democratic Party has been the bedrock of Japanese conservative politics, maintaining near-uninterrupted control over the government since the postwar era. However, the 2025 Senate election revealed deep cracks in its dominance, as public frustration with the LDP reached a critical threshold, creating an opening for new conservative forces to gain traction.

The first factor driving this shift is the perception of the LDP as a stagnant and corrupt institution. Decades of near-continuous rule have led to accusations of political inertia, with recent years marked by a series of high- profile scandals involving political funding and ministerial misconduct. These incidents have eroded public trust, particularly among younger voters and urban middle-class citizens, who increasingly view the LDP as emblematic of an outdated, self-serving political establishment. This ‘LDP fatigue’ has fuelled demand for alternative political voices. The Sanseito and Japan Conservative Party have skilfully positioned themselves as champions of a ‘new conservatism’, promising to break from the LDP’s entrenched practices and offer a fresh vision for Japan’s future. By emphasizing transparency and a return to core conservative values, these parties have successfully attracted disillusioned LDP supporters.

Second, internal divisions within the LDP have exacerbated its vulnerabilities, paving the way for the rise of new conservative players. The LDP has historically accommodated a broad ideological spectrum, from pragmatic, economy-focused moderates to hardline nationalists and traditionalists. However, the long tenure of former prime minister, Shinzo Abe, whose nationalist policies galvanized the party’s right wing, also exposed fault lines within the party. Since Abe’s departure, tensions between the nationalist factions and more liberal or centrist elements have intensified, particularly as the influence of the Abe faction has waned. This ideological fragmentation has left many conservative voters dissatisfied with the LDP’s increasingly ambiguous policy stances. The Sanseito, in particular, has capitalized on this discontent by promoting a clear nationalist agenda, emphasizing ‘politics for the Japanese people’ and appealing to voters who feel the LDP has drifted from its conservative roots. Similarly, the Japan Conservative Party has gained ground by advocating for traditional values and a robust national identity.

The third key factor in the rise of these parties is their adept use of digital platforms to expand their reach. Unlike the LDP, which has relied heavily on traditional campaign strategies such as grassroots organizing and established media, the Sanseito and Japan Conservative Party have embraced social media platforms like YouTube and X (formerly Twitter) to engage directly with voters. These platforms have proven particularly effective in reaching younger demographics and politically disengaged citizens who are less likely to consume traditional media. The Sanseito, for instance, has used online content to disseminate its message, blending populist rhetoric with appeals to national pride. The Japan Conservative Party has similarly leveraged digital tools to build a grassroots movement, resonating with urban youth and rural conservatives alike. This strategic use of technology has allowed these parties to bypass the LDP’s traditional dominance and cultivate a broad, diverse support base.

A worsening security environment and rising nationalism

The rise of new conservative forces is also deeply tied to Japan’s increasingly precarious security environment, which has fuelled a surge in nationalist sentiment. Japan faces a complex array of geopolitical challenges, including China’s aggressive maritime expansion, heightened tensions in the Taiwan Strait, North Korea’s ongoing nuclear and missile programs, and growing military cooperation between Russia and North Korea. These external threats have heightened public anxiety and strengthened calls for a more assertive, self- reliant Japan, creating fertile ground for nationalist political movements.

China’s growing assertiveness in the South and East China Seas has significantly amplified Japanese concerns about national security. Its frequent incursions into waters near the Senkaku Islands and its military buildup in the Taiwan Strait have raised fears of a potential conflict that could directly involve Japan. By 2025, the prospect of a Taiwan contingency has become a pressing concern, prompting a re-evaluation of Japan’s reliance on the US–Japan security alliance. The re-election of the Trump administration in 2025, with its ‘America First’ policies and emphasis on reducing military commitments to allies, has further underscored the need for Japan to bolster its own defence capabilities. The Sanseito and Japan Conservative Party have seized on this sentiment, advocating for ‘autonomous defence’ and a stronger assertion of Japanese sovereignty. These policies have resonated with voters anxious about external threats and sceptical of over- reliance on the United States.

North Korea’s provocations, including missile tests that frequently pass over Japanese territory, have further intensified public fears. Coupled with Russia’s ongoing aggression in Ukraine and its deepening military ties with North Korea, these developments have highlighted the volatility of Japan’s geopolitical environment. The new conservative parties have responded by promoting a vision of a ‘strong Japan’, advocating for constitutional amendments to expand Japan’s military capabilities and significant increases in defence spending. These proposals have found particular resonance among rural conservatives and older voters, who prioritize national security and view these parties as offering bold solutions to pressing threats.

The Trump administration’s inward-looking policies have also indirectly fuelled Japanese nationalism. By raising doubts about the reliability of the US–Japan alliance, the administration has prompted calls for greater Japanese military and diplomatic autonomy. The Sanseito and Japan Conservative Party have capitalized on this uncertainty, emphasizing the need to ‘protect Japan without relying on foreign powers’. This rhetoric has tapped into latent nationalist sentiments, positioning these parties as defenders of Japanese independence and pride.

The leader of the Sanseito, Kamiya, has recently declared that all national parliament members affiliated with the Sanseito will visit Yasukuni Shrine, and he will likely continue to advocate for such visits as a duty. Although the Sanseito and the Japan Conservative Party are minor political forces with little influence on Japanese diplomacy, their stance of mandating visits to Yasukuni Shrine is certain to cause friction in relations with South Korea and China. Considering the realities of East Asian security, Japan is required to pursue further security cooperation with South Korea. However, if Japan-first movements like the Sanseito become prominent within Japan, there is a risk that Japan–South Korea security cooperation could regress.

Economic stagnation and rising xenophobia

Domestically, Japan’s prolonged economic stagnation and growing social discontent have provided a critical backdrop for the rise of new conservative forces. Since the collapse of the asset bubble in the 1990s, Japan’s economy has struggled to regain its former dynamism, with little progress by 2025. Declining real wages, rising inflation driven by a weakening yen, and persistent economic challenges have eroded living standards, fuelling widespread frustration. These economic grievances have aligned with the ‘Japan First’ rhetoric of the Sanseito and Japan Conservative Party, driving their growing popularity.

The economic downturn has also fostered a sense of lost national identity, as Japan’s once-robust status as an economic superpower has been overshadowed by the rise of China and other emerging economies. The weakening yen has exacerbated the cost-of-living crisis, with higher import prices squeezing household budgets. This economic malaise has cultivated a nostalgic desire for a return to a ‘strong and prosperous Japan’, a sentiment that new conservative parties have effectively harnessed. Their calls to ‘Make Japan Great Again’ echo the aspirations of voters who feel left behind by globalization and economic decline.

The influx of foreign workers, driven by Japan’s aging population and labour shortages, has also sparked xenophobic sentiments among some segments of the population. While foreign labour is critical to addressing workforce shortages, particularly in industries like construction and caregiving, it has led to misguided perceptions that ‘foreigners are taking Japanese jobs’. These sentiments are particularly strong in rural areas and among low-wage workers, where economic insecurity is acute. The Sanseito and Japan Conservative Party have exploited these fears, advocating policies to ‘protect Japanese employment’ and ‘reform foreigner- favoured policies’. Such rhetoric has resonated with economically vulnerable voters, amplifying the parties’ appeal.

Widening social disparities have further fuelled this trend. The rise of the digital economy and globalization has deepened divides between urban and rural areas, as well as between affluent and working-class communities. In rural regions, resentment against ‘Tokyo-centric elitism’ and globalist policies has grown, creating an opening for new conservative parties to position themselves as champions of ‘politics for the Japanese people’. By framing their agenda as a defence of local interests and traditional values, these parties have gained significant traction among rural voters.

Economic stagnation and rising xenophobia

The surge of the Sanseito and Japan Conservative Party in the 2025 Senate election reflects a complex interplay of domestic and international factors. I will omit the factors mentioned above, but as a result of this election, the Ishiba administration has led the Liberal Democratic Party to its second consecutive defeat in national elections, following last September. Some argue that Japanese politics entered an era of drift after the significant loss in last September’s election. However, the results of this Senate election suggest that Japan’s political instability is likely to intensify further. When viewed in the context of East Asian security, there is concern about how the Trump administration will perceive Japan’s political instability. During Trump’s first term, Japan’s political foundation was solid under the Abe administration, which made Japan–US relations exceptionally strong and stable.

However, the current situation is entirely different, and it remains uncertain whether Japan, having lost its political stability, can maintain stable and functional relations with the Trump administration or the subsequent administration. While it is unlikely that the Japan–US alliance will become hollow overnight, the outcome of this Senate election is undoubtedly unfavourable for East Asian security.

This shift signals a potential realignment of Japan’s conservative political landscape. The LDP now faces the challenge of retaining its traditional support base while countering the rise of these new competitors. The success of the Sanseito and Japan Conservative Party in sustaining their momentum will depend on their ability to translate populist rhetoric into concrete, actionable policies. However, their rise also carries risks, including the potential for heightened nationalism and exclusionary policies that could deepen social divisions.

At the same time, these parties have provided a new channel for addressing public grievances, offering a voice to segments of the population that feel overlooked by the political establishment. Their ability to maintain and expand their support will shape Japan’s political trajectory in the years ahead, determining whether this surge represents a fleeting protest vote or the beginning of a broader transformation in Japanese politics.

Policy Recommendations:
Responding to the rise of new conservative forces and ensuring Japan’s political stability

1. MITIGATING POLITICAL POLARIZATION AND PROMOTING INCLUSIVE DIALOGUE

The rise of emerging conservative parties reflects not only dissatisfaction with established parties but also growing signs of societal fragmentation. Both the ruling and major opposition parties should avoid reacting with confrontation, and instead foster broad-based national dialogue. In particular, it is essential to incorporate the voices of youth, rural communities, and other segments that have been politically marginalized into policymaking processes.

2. STRENGTHENING CONSISTENCY AND ACCOUNTABILITY IN SECURITY POLICY

Amid rising instability in East Asia and declining confidence in U.S. security commitments, Japanese nationalism has been inflamed. The government must maintain consistency in its security policies while reinforcing accountability through clear and transparent communication with the public. In sensitive areas such as constitutional revision and expanding the role of the Self-Defense Forces, a cautious approach that prioritizes thorough public debate and national consensus is indispensable.

3. PURSUING ECONOMIC REVITALIZATION WHILE PROMOTING SOCIAL INTEGRATION

Japan’s prolonged economic stagnation and widening inequalities have created fertile ground for exclusionary and xenophobic sentiments. To counter this trend, economic policies must be redesigned to not only restore growth but also strengthen the social fabric. Immigration and foreign labour policies, in particular, should adopt an inclusive approach that emphasizes coexistence. In addition to addressing immediate labour shortages, the government must implement comprehensive education, integration, and settlement support programs to prevent social friction.

4. REVIEWING POLITICAL INSTITUTIONS, INCLUDING ELECTORAL REFORM

The current electoral system has structural vulnerabilities that allow populist or radical forces to rapidly gain seats through digital mobilization. Over the long term, Japan should consider institutional reforms, including adjustments to the proportional representation system, electoral districting, and public funding rules for political parties. Such reforms should aim to balance respect for diverse public opinion with the need to maintain the stability of democratic governance.

Conclusion

In conclusion, the rise of a ‘Japan First’ style conservatism raises concerns that it may negatively affect tensions with China over the Senkaku Islands and the Taiwan Strait. Up to now, Japan has adhered to a stance of not fueling or aggravating security frictions with China, instead consistently taking a position of restraint to avoid escalation. By contrast, ‘Japan First’ conservatism is based on the principle of defending one’s own security independently, and it remains uncertain to what extent it takes the other side’s perspective into account. As a result, discord and friction could naturally expand. Moreover, ‘Japan First’ conservatism may not have strong capabilities in conflict management.

In recent years, Japan–South Korea relations have been stable, largely because the Kishida and Ishiba administrations of the Liberal Democratic Party have objectively understood Japan’s position in the spheres of military and economic security, and have managed bilateral issues in a way that enabled the building of good relations. It is unclear to what degree ‘Japan First’ conservatism would recognize the need for such conflict management with South Korea, and there is a risk that it might instead take the initiative in worsening relations.

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