Isono Kazumasa serves as a historical military commander for the Azai clan during their conflict with Oda Nobunaga. He engages in critical battles, including the assault on Yokoyama Castle, where Azai and Asakura forces unite against Nobunaga's troops reinforced by Tokugawa Ieyasu. At the Battle of Anegawa, he employs aggressive tactics to breach multiple Oda camps, driven solely by the objective of reaching and killing Nobunaga in his main encampment. During this assault, he directly confronts adversaries Maeda Toshiie and the ninja Chidori. His defining traits include distinctive "Anti-Gravity Hair" and his role as a "Sword Fighter."