As the cannon is prepared to launch, Torii spots Ginjiro on the platform, engaging in battle against him. When the rocket is ignited, the ice on the platform begins to crack, the rocket kills a crowd in canoes, and the platform itself is destroyed. Oriku is upset that her project was a failure. When Seikichi, Sora, and Shunpei returns to the island, the residents suffer from thrift laws as a consequence of the faltered cannon. As Ginjiro finds out that Torii wanted to attack foreign ships, he also realizes that Toyama wants to bomb foreign countries. Seikichi proceeds to launch the rocket the next day, all to show everyone the greatest creation ever made, despite Toyama's plans. Akai encounters the blue sky beast, who was disguised in human form.
鍵屋が江戸で一番の花火屋だという証を立てるためにおりくが作り上げたのは、異国船を打ち払うための大砲だった。大きな花火の打上げだと噂を聞きつけた、近在の者が集まってくる。鳥居、水野、遠山、それぞれの思惑は交錯し、巡りつく先は…。
