도사 번
Nakae was born in Kōchi, Tosa Domain (present day Kōchi Prefecture). His father was an "ashigaru", or lower ranking foot soldier in the service of the Yamauchi clan of Tosa. Having displayed an early aptitude for Western learning, after studies at the domain academy, Nakae was selected to study French and Dutch at Nagasaki and Edo. Later, he worked as a translator for the French minister to Japan, Léon Roches.