It is widely and increasingly acknowledged that social capital plays a crucial role in the economic performance, which covers various facets of human behavior. A growing body of literature has sought to investigate the role of social capital mainly in heterogeneous societies such as USA, whereas works concerning homogeneous society have not yet sufficiently been provided. From the comparative point of view, researches on homogeneous society are called for. In this paper, therefore, I aim to introduce researches to explore how social capital affects the socio-economic outcomes of Japan, which is considered as a relatively homogeneous society. Recent preliminary empirical works attempted to provide the interesting evidence in Japan, which covers the following topics. (1) Criminal prevention, manner of driving, suicide, lawyers demand for conflict resolution (2) cinema and baseball attendance, (3) voter turnout, response to Census, and protection against natural disasters, (4) diffusion of knowledge, efficiency improvement and industrial development, (5) quality of life in terms of health, (6) formation of trust in a community. It follows from them that the social capital enhances the collective action, leading to benefit, however such effect has changed over time.
