The share of women in managerial and leadership roles in Japan – in both the public and private sector – are among the lowest across the globe. This paper empirically examines what drives these large gender gaps in leadership in Japan, using the SVAR model. Results suggest — (i) cultural norms where women take up significantly more burden of household and childcare work; (ii) Japan’s unique employment practices (non-regular employment, long in-person working hours); and (iii) the availability of childcare facilities — are the key drivers. Further progress on workstyle reforms, more flexible labor markets, improving the quality of childcare facilities, and raising paternity leave usage will help close these gaps.