Although gender-neutral Japanese names may be becoming more common than in previous generations (Satō, 2007), data also suggest that new gender-based naming patterns are emerging (Unser-Schutz, 2023). With their ever-growing numbers, baby-naming guides may play an important, but underexamined, role in changing names for children and people's perceptions of gender in names. This article fills this gap by 1) analyzing how gender is discussed in the advice and 2) analyzing kanji [Chinese characters] for names suggested in two editions of the guides by the popular Tamahiyo childrearing brand. Although there are few explicit discussions of gender, closer inspection reveals gender to be treated as an a priori category. The guides also make many assumptions about boys’ and girls’ names. The more recent edition was more authoritative in voice and less balanced in its assignment of gendered names across semantic image categories, creating distinctly gendered patterns. Given the otherwise high-level of innovativeness of Tamahiyo (Kobayashi, 2009), these results confirm that conservative trends toward gendered naming remain strong. Changes in Tamahiyo's voice may be explained by consumer demand, backlash toward recent naming trends, and its maturation in childrearing discourse over time