Nanma was born in 1823 in the castle town of Aizu-Wakamatsu castle, and as a child attended the han school Nisshinkan and distinguished himself as an excellent student. At age 25, at the orders of the domain, he began studying at the Shôheizaka gakumonjo; while in Edo he also began studying Western studies under Sugita Seikei and Ishii Mitsutarô, among others.
In 1855, he traveled the Kansai, and investigated local customs to report back to his domain. Then, for six years beginning in 1862, he spent time in Karafuto, working towards its annexation or integration. In 1868, he returned from Karafuto and became the head of education at the Aizu han mansion. During the Boshin War, at the orders of his domain, he laid low in Osaka; returning to Aizu, he found the castle destroyed, and found himself confined in Takada han.
Following the Meiji Restoration, Nanma became head of education in Kyoto prefecture, then later worked for the Dajokan and the Ministry of Education, and became a professor at the University of Tokyo and at normal schools and women's normal schools. Along with Nishimura Shigeki, he helped found the Nihon Kôdôkai, a moral philosophy group.
- Explanatory plaques at Nanma's grave in Yanaka Cemetery, Tokyo.