Women are underrepresented among candidates and elected officials at a
ll levels of government in Japan. This analysis examines the relative
effects of electoral system, district magnitude, candidate opportunity
, party nomination, and the political mobilization of women in recent
Japanese elections. Empirical findings from tests of hypotheses agains
t district level data from elections to the Upper House and Lower Hous
e of the Japanese Diet, Tokyo Metropolitan Assembly, and Tokyo Special
Ward assemblies are reported. Although the analysis indicates that in
stitutional factors fail to account for the underrepresentation, it al
so shows that recent elections have been crucial thresholds in increas
ing women's representation.