Okoku Okamatsu studied under Banri Hoashi.
Okoku Okamatsu was appointed an instructor at the Shoheiko, the Shogunate college. After the Meiji Restoration (1868), he served in the Imperial Household Ministry and was appointed professor at Tokyo University. He founded Shosei Shoin, a private school, where hundreds of youths studied. Among his disciples was Chomin Nakae, noted publicist.