Gintoki and Nizo battle to the death on the deck of Takasugi's ship. The anti-battleship weapon Benizakura has infiltrated Nizo's mind, driving Nizo out of control. Gintoki fights back with a sword forged by Tetsuko. Nizo attacks with overwhelming strength, but slowly, the battle begins to turn in Gintoki's favor. Meanwhile, within the ship, Takasugi plans to use the Benizakura to overthrow the shogunate, but he is confronted by Tetsuya, the man who forged the Benizakura, Tetsuya's younger sister Tetsuko, and Katsura.
And an object that exists for a single purpose is strong, flexible and beautiful.
Y un objeto que existe para un único 
propósito es fuerte, flexible y hermoso.
E um objeto que existe para um único
 propósito é forte, flexível e belo.