Born the son of Sakura han retainer Okamoto Chiharu, Shunkai became a boarding student the Juntendô and studied Dutch language and medicine under Satô Taizen and Satô Takanaka. He then became an official court physician in service to the domain, and following a set of domainal medical reforms in 1866, was named Third Court Physician.
After Satô Takanaka retired in 1874, he adopted Dôan, granting him the name Satô Shunkai, and naming him head of the Juntendô. As head of the school, Shunkai oversaw the conversion of two of the Juntendô's tatami rooms into a single Western-style room, among other renovations to make the building better suitable for a modern/Western-style medical school and hospital. Shunkai and others associated with the Juntendô also served as medical officers for the Sakura Infantry Hospital.
- Pamphlets available at the Juntendô Memorial Buildings Museum.
- After his own name, Yamaguchi Shunkai, prior to being adopted by Taizen and becoming Satô Takanaka.