Kōtoku was born in 1871 to a mother who came from a lower samurai family, and to a father who died shortly after his birth. Born in Tosa Province, one of the key supporters of the Meiji Restoration, he became influenced by the growing opposition to the new government. Tosa was a hotbed of resistance largely due to the discontent of samurais, whose power was declining, and Kōtoku became at a young age an ardent supporter of the pro-democracy Liberal Party.