Set in the Edo period of Japan, "Oh! Edo Rocket" blends historical elements with science fiction and comedy. The narrative centers on Seikichi Tamaya, a firework maker in the Tenpō era, a time when the shogunate strictly enforced sumptuary laws to curb extravagance. Seikichi dreams of creating the most spectacular fireworks, but his ambitions are stifled by the oppressive regulations. His life takes an unexpected turn when a mysterious girl named Sora arrives, claiming to be from the moon and requesting his help to build a rocket to return home.

As Seikichi becomes entangled in Sora's quest, the story expands to include a colorful cast of characters, each with their own motivations and secrets. Among them is Genzō, a bumbling yet determined government official tasked with enforcing the sumptuary laws, and his assistant, Shunpei, who harbors a crush on Sora. The narrative also introduces the enigmatic Kagami Group, a shadowy organization with ties to the shogunate, which seeks to exploit Sora's advanced technology for its own purposes.

The plot weaves together themes of ambition, rebellion, and the clash between tradition and innovation. Seikichi's journey to build the rocket becomes a metaphor for breaking free from societal constraints, while Sora's presence challenges the characters' understanding of their world. The series balances its comedic moments with deeper explorations of loyalty, sacrifice, and the human desire to reach beyond limitations.

Throughout the story, historical and fantastical elements intertwine, creating a unique setting where samurai coexist with alien technology. The narrative builds toward a climactic confrontation as Seikichi and his allies race against time to complete the rocket, facing both external threats and internal conflicts. The resolution ties together the characters' arcs, offering a mix of triumph and bittersweet reflection on the cost of pursuing dreams.

"Oh! Edo Rocket" stands out for its imaginative premise, blending historical drama with science fiction, and its ability to balance humor with poignant storytelling. The series explores universal themes through its eclectic cast and inventive narrative, making it a distinctive entry in the anime genre.