Growing evidence reveals that candidate issue engagement differs between men and women. However, recent research suggests that individual-level differences among candidates should be small under the strategic incentives inherent in single-member district elections that encourage party rather than personal-vote seeking. We examine whether men and women candidates emphasize different issues in their electoral campaigns and if the magnitude of the gender gap varies under different electoral rules. Our analysis of 7497 Japanese election manifestos spanning more than 20 years, from 1986 to 2009, reveals significant gender differences in the issues candidates emphasize in their electoral campaigns, regardless of party affiliation or other attributes. Moreover, these differences remain salient after an extensive change from a multi-member district to single-member district electoral system.