In 1591, Chosokabe Motochika moved his headquarters from Okosaka Castle to the summit of Urado Hill, developing this mountaintop fortification into a full castle with a three-story keep overlooking Katsurahama Beach. Having just lost his heir Nobuchikar at the Battle of Hetsugi River, Motochika built the castle as a military base in anticipation of the Korean campaign and to control Tosa's coastal waters. In May 1599, Motochika died of illness at his Fushimi residence, and his remains were interred at Tenpo-ji Hill in Nagahama, Kochi. Urado Castle stands as the place where Shikoku's greatest warlord spent his final years.