In a modern nation governed by a Martial Shogun, where samurai command significant respect, the Sakakido family has identical twins. Kou, the brother, is quite feminine and excels in cooking, cleaning, and arts and crafts. Tsukiko, the sister, is masculine, enjoys fighting, and is a combat genius. The twins discover Samurai High School, an institution where men prove their strength and women demonstrate their femininity, but their only option to attend is to swap places. If they are caught cheating, they face execution, forcing them to bridge their gender differences and keep their secret.