The Amanto have brought despair to the samurai of feudal Japan, who have lost their swords and are now treated with contempt. The aliens wreak havoc without mercy, leaving the samurai feeling hopeless. Kotarou Katsura, leader of the Anti-Foreigner Faction, takes matters into his own hands and plans to eliminate the Amanto using aggressive tactics. He prepares to face the skilled samurai group, the Shinsengumi, with a massive mecha. Meanwhile, Gintoki Sakata and his friends had planned to observe the beautiful cherry blossoms. However, their peaceful outing is disrupted when the Shinsengumi confront them, stating that Gintoki had taken their spot for flower-viewing. This leads to a heated argument that ultimately ends with a game of rock-paper-scissors, which turns out to be an intense and brutal affair. Despite the conflict, the group continues on with their plans to admire the cherry blossoms.