Linguistic instrumentalism, which underscores the importance of English skills for work and for achieving individual economic success, has influenced language education policies and proliferated the language teaching and testing industry in Japan. Linguistic instrumentalism is linked to the notion of human capital (i.e., skills deemed necessary for the knowledge economy) and the unstable employment conditions of neoliberal society. Focusing on the role of learning and using English for work in Japan, this qualitative study investigates the aspirations and experiences of adult workers learning English and the views of managers of manufacturing companies about the role of English and English tests. In-depth interviews revealed that the learners' aspirations and work experiences, and the managers' views do not always confirm linguistic instrumentalism. Rather, career successes are influenced by gender, geography, and other factors. The findings indicate that language tests actually create the demand for learning English through measuring "efforts" to learn in the knowledge economy.