Although there has been a growing number of works on Korean residents in Japan (zainichi), this largest ethnic minority of Japan hardly matters to students of modern Japan beyond the context of disproving the myth of Japan's homogeneity. With the increased attention to the complexity of early twentieth-century Japan as an empire, it becomes imperative to consider the impact of the colonized in the making of the Japanese metropole. Upon the annexation of Korea, Japan carried out various colonial projects, such as the cadastral survey (1910–18) and the rice production increase plan (1920–34). The consequences were the growth of Japanese landlords and agrarian expropriation in Korea.

The Proletarian Gamble tells the story of these Korean peasants who searched for wage work and ended up becoming day laborers in Japan with no guarantee of work or housing during the post–World War I recession. By analyzing the “proletariat conditions” of these Korean migrants in the informal sector of Japanese economy, this book demonstrates the ways in which these colonial populations constituted the fabric of Japanese political, economic, and cultural materiality amid ethnic discrimination. Ken C. Kawashima's analysis of the contingencies that these “surplus populations” faced in the “continually discontinuous process of commodification” of their labor power in interwar Japan (p. 10) sets a new standard in the study of Koreans in Japanese social and labor history.

The first two chapters present the context in which the colonial state and capitalists brought the impoverished Korean peasants to Japan as cheap, temporary, and nonunionized industrial workers during the World War I manufacturing boom, and describe how they became a growing, surplus population whose most urgent problem was the insecurity of their employment when the economic boom ended. The deceptive recruitment process, harsh labor conditions, and state-led ethnic discrimination—such as the setting of the Korean wage lower than Japanese—led the Koreans to form an organized labor movement in Japan, thus heightening the authorities’ fear of their class movement, which might be combined with their independence movement.

Chapters 3 and 4 introduce two specific forms of exploitation of Koreans in Japan: intermediary exploitation by labor managers and brokers and landlords' discriminatory leasing practices against Koreans. Chapter 5 introduces the Sōaikai, a state-funded police supplement institution that worked as a powerful labor broker for Koreans in imperial Japan. Through the management of dormitories, labor exchange offices, and clinics, it employed the “divide and conquer” tactic toward Koreans by spreading a particular dual imagery of Koreans as innocent or unruly. The final chapter turns to a state institution, the Unemployment Emergency Relief Program, which individualized the unemployed Koreans, leading them to compete against each other rather than rising as unified labor movement.

The book contributes significantly to the fields of empire studies, labor history, and Japanese history, first by contextualizing the demographic flow from Korea to Japan, thus demonstrating the linkage between rural and urban expropriation in the process of capitalist commodification of land and labor across the colony and metropole. Second, it brings the unemployed and day labor migrant workers into the picture of Japanese labor history by extending the concept of “proletariat” beyond the factory-based laborer population. Third, Kawashima introduces important Japanese-language source materials on Koreans in Japan to the English-language scholarship, especially the key official documents collection that the late zainichi historian Pak Kyŏngshik compiled over several decades. Finally, Kawashima highlights the need for a contextualized reading of the colonial documents, which tend to reduce these workers' problems to inherently “racialized or ethnicized” Korean phenomena (p. 19).

As Pak reminds us in his Japanese documents collection, reading between the lines and considering what is absent is as important as knowing what is preserved in the colonial archive. I applaud Kawashima's sensitivity to the “fiction of the imperial rhetoric of assimilation and equality” (p. 121) and his acknowledgment of the fact that the majority of these largely uneducated colonial migrants did not speak the language of the metropole (pp. 242 n. 39, 256 n. 60). Nevertheless, he engages with no Korean-language primary or secondary text. Nor do the names of Korean men and women appear adequately in this otherwise thoroughly researched study on Korean workers in interwar Japan. While the book successfully demonstrates the diverse controlling measures of the state and state apparatuses over Koreans' travel, wages, and housing, ordinary Koreans remain largely nameless, voiceless, and faceless. Although it might be too much to ask a historian to imagine the empire beyond the boundary of the colonial archive, one wonders how the incorporation of Korean materials—such as contemporary Korean periodicals that include the memoirs and interviews of these colonized migrant workers expressing their feelings, thoughts, despair, and hope in their mother tongue—would have enhanced Kawashima's efforts to represent Koreans in their path to the “proletarian gamble” in Japan during the 1920s and 1930s. Such epistemological sensitivity and flexibility toward various dispersed historical texts would lead us to a better understanding of what it meant to be a working class social being under the influence of colonialism. This first-rate, indispensible reading on Korean workers in the Japanese empire moves us one step forward toward that goal.