In the year 2025, Earth sends an expedition to Mars in the spaceship Izanami. A huge rock formation is discovered beneath the surface, and is transported back to earth. On the way back, the rock's temperature soars, causing the Izanami to explode and crash-land in Tokyo, leaving a large crater. The rock hatches into a colossal alien life form, which proceeds to attack Japan with bolts of energy from its many appendages and orifices. Missiles, tanks, and aircraft all attack but fail to destroy Negadon (the name of the creature, although it is never stated on screen), whose thick exoskeleton protects it from conventional weaponry.
At the same time, Ryûichi Narasaki, a downcast robotics constructor, is still devastated by the incident that cost him his left eye and the life of his only child, a young daughter. The incident was caused by the malfunctioning of his masterpiece, the giant prototype super-robot MI-6 2 Miroku. Because of the ominous threat of Negadon, Narasaki faces the painful choice of reactivating (and piloting) Miroku to destroy Negadon and save the world. After an epic battle, Narasaki (in Miroku) hauls Negadon into the upper atmosphere and destroys the space creature.
- Kether Donohue as Emi Narasaki (voice) (as Annice Moriarty)
- Dan Green Dan Green as Seiji Yoshizawa (voice)
- Masafumi Kishi Masafumi Kishi as TV announcer / Narrator
- Takuma Sasahara Takuma Sasahara as Seiji Yoshizawa
- Sean Schemmel Sean Schemmel as Ryuichi Narasaki (voice)
- Dai Shimizu Dai Shimizu as Ryuichi Narasaki
- Marc Thompson Marc Thompson as TV Announcer / Narrator (voice)
- Akane Yumoto Akane Yumoto as Emi Narasaki
- Directed by Jun Awazu
- Written by Jun Awazu
- Produced by Kazuki Sunami
- Music by Shingo Terasawa, Akane Yumoto ("Dream in True Color: The Sky in 2015")
- Cinematography by Jun Awazu
- Edited by Jun Awazu
Writing for the New York Times, Neil Genzlinger remarked that Negadon: The Monster from Mars "looks great and even has a respectable dose of the character development and backstory that anime sometimes spurns... The setup is lovely, but the film seems in a hurry to get to the big clash, as if desperate not to violate some anime time limit. Too bad; it might have worked at feature length." Carl Kimlinger of Anime News Network gave a more muted endorsement: "Negadon is, at heart, a distillation of everything that Jun Awazu loves about the kaiju eiga. At only 25 minutes, there isn't time for anything else. Of necessity, this means jettisoning much of what gives the best kaiju movies their resonance; character depth and interaction, social commentary, and (as silly as it sounds) any depiction of the human cost of fighting a giant monster are all excised, inherently limiting the scope of the intended audience. This isn't a movie for everyone; Negadon is instead aimed squarely at those of you who stand up and cheer when a giant robot breaks out its drill arm."