This thesis offers a macro-historical analysis of the emergence of the Japan Innovation Party (Ishin) and its core policy agenda, moving beyond short-term or event-driven explanations that dominate existing scholarship. Ishin represents Japan’s firs...
This thesis offers a macro-historical analysis of the emergence of the Japan Innovation Party (Ishin) and its core policy agenda, moving beyond short-term or event-driven explanations that dominate existing scholarship. Ishin represents Japan’s first successful regional party to achieve sustained electoral dominance in a major prefecture, diverging sharply from the postwar national pattern of Liberal Democratic Party (LDP) dominance. While a substantial body of literature has sought to explain Ishin’s rise, most studies emphasize leadership charisma, populism, institutional reform, or electoral contingencies after 2010. Such approaches, however, tend to overlook the deeper historical and structural conditions that made Osaka a uniquely fertile environment for the party’s emergence.
This study advances an alternative perspective by asking why Ishin could emerge specifically in Osaka, and how its signature policies—most notably the Osaka Metropolis Plan and the subcapital vision—were shaped by the region’s long-term political and economic context. Rather than treating Ishin as a sudden reaction to national-level political disillusionment, this thesis conceptualizes the party as an endogenous product of Osaka’s historical trajectory.
Empirically, the study reconstructs Osaka’s postwar electoral history by analyzing House of Representatives elections from 1958 onward and systematically comparing Osaka’s electoral patterns with national trends. This long-run analysis examines whether electoral configurations commonly associated with Ishin’s post-2010 dominance—such as weak LDP control and openness to new political forces—were already present prior to the party’s formation. In addition, the thesis assembles and analyzes long-term, Osaka-specific economic data that have been largely neglected in existing research. By doing so, it evaluates how Ishin strategically interpreted and incorporated Osaka’s relative economic stagnation into a coherent reform agenda.
The central finding is that Ishin’s emergence and consolidation cannot be understood independently of Osaka’s distinctive political economy. Politically, Osaka has long exhibited electoral volatility and recurrent party replacement, creating structural openness to new entrants. Economically, Osaka’s experience of relative decline within Japan’s centralized political economy endowed Ishin’s reform proposals with credibility and urgency. Ishin’s political “newness” is thus interpreted not as a stylistic innovation, but as an institutionalized response to accumulated regional constraints.
The contribution of this study lies in filling a critical gap in the literature. Although existing research widely acknowledges Ishin as an Osaka-based party, few studies have systematically analyzed the party through the lens of Osaka’s long-term political and economic history. Whereas prior work has focused on the post-2010 period and short-term electoral outcomes—the “trees”—this thesis reconstructs the broader “forest” of Osaka’s political economy, demonstrating that the structural roots of Ishin’s rise were planted well before its formal establishment.