In January 1941, the Japanese female population in New Caledonia included the Japan-born as well as former French citizens and subjects, Dutch subjects (primarily Javanese) and local Indigenous Kanak women who were married to Japanese men. Before the enactment of a new French Nationality Law in August 1927, French women who married non-French citizens became citizens of their husband’s country and therefore French women who married Japanese men became Japanese. After the change in the law, French women who married Japanese retained their French citizenship. Kanak and Dutch women who married Japanese men also became Japanese. The number of Japan-born women was low compared to the number of Japanese men, primarily because the French authorities did not permit yobiyose (proxy marriages by correspondence). This article is an exploratory study of the three categories of Japanese women who were resident in New Caledonia at the time of the outbreak of the Asia-Pacific theatre of war in December 1941: heritage, Japan-born and Japanese-by-marriage. It discusses the different effects that marriage had on the women depending on their backgrounds.