Saruhashi became the first woman in Japan to earn a PhD in chemistry from the University of Tokyo.
Alongside receiving her Doctor of Science degree, Katsuko Saruhashi's doctorate, conferred on March 25, 1957, is also recognized as making her the first woman in Japan to earn a PhD in chemistry specifically from the University of Tokyo, one of the nation's most elite and historically male-dominated research institutions.
This distinction highlights the scale of the barrier she overcame: chemistry, as a discipline, had been essentially closed to women at the highest doctoral levels in Japan prior to her achievement. Her success demonstrated that women could not only participate in but excel at the most rigorous levels of chemical and geochemical research.
The achievement resonated widely within Japan's scientific community and beyond, as it coincided with a broader post-war push to modernize and internationalize Japanese science. Saruhashi's doctorate gave her credibility and standing that she used to advocate fiercely for other women entering scientific fields.
Her example directly inspired the establishment of support networks for women scientists in Japan, including her founding of the Society of Japanese Women Scientists in 1958. Decades later, she would also create the Saruhashi Prize, explicitly to help other women achieve similar recognition in fields where they remained underrepresented.