Hei Ying 黑嬰 (1915–1992) wrote prolifically about the “southern isles,” where he—a Hakka from Sumatra—was born. Written for a sophisticated urban readership in China that was curious about the exotic and erotic Nanyang, Hei Ying's 1930s fiction foregrounds questions of Chinese ethnicity and nation. Ethnicity interacts with gender against sultry and desultory backgrounds, with improper patriotic or sexual tendencies attracting narrative punishment. Drawing on three pieces of his short fiction from the 1930s, this article argues that Hei Ying's theme of sexual temptation in the tropics rehearses European colonial (or Han majority) views of the impulsive, sultry native, an image that is contrasted with Republican Chinese primness. The bourgeois woman awakening to Chinese ethnonationalism and rejecting sensuality in favor of patriotism makes her an ancestor to the sexless heroines of Chinese revolutionary culture, including some Hei Ying would write later. The sensuality of the tropics thus operates as a foil for passions correctly channeled—toward nation (and eventually also party-state).