Purpose: This paper aims to examine the impact of three key factors ��� corporate social responsibility (CSR) awareness, CSR affordability and CSR management system (CSRMS) sophistication���on the CSR performance of Japanese firms. Design/methodology/approach: Using responses to 36 items developed on the Global CSR standard of ISO26000, two CSR indexes were constructed to assess the CSR management system sophistication and performance of Japanese firms. The relationship between the three key variables (CSR awareness, affordability and management system sophistication) and CSR performance was then examined through a partial least squares (PLS)-based structural equation model. Data were collected through a questionnaire survey of 146 firms. Findings: The results of the study found a positive relationship between CSR performance and three exogenous variables (CSR awareness, affordability and management system sophistication). Furthermore, the study found that CSRMS sophistication played a mediating role in the relationship between CSR performance and firms' CSR awareness and affordability. Research limitations/implications: The study was limited to examining the CSR practices of a major province in Japan, which may hinder the generalisation of the findings to the rest of the country. Moreover, the data used for assessing the variables in this study were self-reported by the participating firms, in addition to being cross-sectional. The findings of this study clarified areas that policymakers, including Japan's business associations���Keidanren and Keizai Doyukai, and other relevant parties need to focus on for further improving CSR performances of Japanese firms. Originality/value: This study highlights the role CSR awareness, affordability and CSRMS sophistication play in improving CSR performance. On the one hand, it identifies the critical role CSRMS plays in mediating the relationship among CSR performance, awareness and affordability. On the other hand, it advances CSR theory providing insight for practitioners to generate positive CSR outcomes.