Kochi Castle was constructed by Yamanouchi Kazutoyo, who was enfeoffed with the Tosa domain after the Battle of Sekigahara in 1600. He started the construction of the castle on top of Mt. Otakasakayama in 1601, and moved to the new castle in 1603, when most of the works had been completed.

The castle compounds except the Otemon Gate were burnt down by a fire in 1727, but they were restored to the original forms until 1753. Although the castle has suffered from many crises including the Meiji government order of castle dismantling, natural disasters and World War II, it has been preserved in a good state of form until now, being called “the finest castle in the Nankai district,” or “the Lucky Castle.” It was designated as an Important Cultural Property on August 25, 1950.