Nagaoka

Nagaoka lies in central Tosa, where Okō Castle was the ancestral stronghold of the Chōsokabe family. Chōsokabe Motochika was born there in 1539 and expanded his family's power across Tosa and much of Shikoku. In 1585 he submitted to Toyotomi Hideyoshi's invading forces and retained Tosa alone. He later moved his residence toward the coast, leaving the old mountain stronghold from which his family had begun its rise.