In the futuristic, alien-infested city of Edo, Gintoki and his overworked, underpaid employees - Shinpachi and Kagura - are struggling to make ends meet. They work odd jobs, but avoid anything too risky. However, when Katsura, Gintoki's old friend and leader of the rebel group Joui, goes missing after being attacked, Shinpachi and Kagura start investigating. At the same time, Gintoki accepts a job from the blacksmith Tetsuya, to retrieve the powerful Benizakura sword, stolen by an unknown thief. As the two cases collide, the Yorozuya team discovers a dark conspiracy surrounding the sword. Gintoki decides to confront the enemy directly, and, with some unexpected allies, embarks on his most dangerous mission yet.