As Arioka-jo Castle was a sogamae castle (castle surrounded with a wall with castle town inside the wall), which was a rare case in the Sengoku Period (Japan), and the defense was tight, however, troops of Nobunaga ODA could not bring down partly because of darkness in the night.
しかし有岡城は戦国時代(日本)の城としては珍しい総構えの城で守りが堅く、また夜の暗さで攻め切る事が出来なかった。