Near the end of the shogunate in Japan, Katsura Shogoro and his fellow samurai from the southwestern domain of Choshu enter the dojo of Saito Yakuro, the famed Shindo Munen Ryu swordsmen of Renpeikan in Edo. Katsura is initially not welcomed by the other, senior dojo followers. Undeterred, he focuses on improving his skill not only in swordsmanship but also learning how to repel the foreign British and American ships that threaten their domain.