The Introduction begins by unpacking a 1929 Taiwanese civil case where multiple parties were concerned with the formation of a marriage, showing how the case – and public debates as well as other civil and criminal cases presented in this book – evolved around sociolegal problems across the empire, social customs and new forms of family, masculinity tied to household relationships, and Taiwanese women’s agency. The argument of the circulation of gender ideals is followed using ethnographic and historical backgrounds on marriage gifts, daughter adoption, and premarital sexual relationships in Japan and Taiwan from the late nineteenth century through the 1910s. Grounded in these historical contexts, the Introduction suggests gender was at the center of Japan’s international and colonial relations, the competition surrounding Taiwanese masculinity in society and law, and the contested formation of Taiwanese women’s agency in the colonial courts. The final section outlines the organization of Geographies of Gender by highlighting the shift in narrative from the larger historical circumstances surrounding the Japanese empire to the specific interactions between discourse and colonial law in gendered terms.