Toyotomi Hideyori appointed Sanada Yukimura as the garrison commander due to his experience opposing Ieyasu's army in his castle at Ueda during the Sekigahara campaign. At that time the castle had two moats, which still exist, and Hideyori's engineers created an outer moat by cutting a channel between the canal that existed to the west and the Nekoma stream which flowed from south to north on the eastern side.