[4][5] The mecha's first appearance in the United States was as a part of the Shogun Warriors line of super robot toys imported in the late 1970s by Mattel, then in Jim Terry's Force Five series.

The Vega homeworld has become unstable due to the exploiting of Vegatron, a powerful radioactive ore. Seeking to expand his militaristic empire and find a substitute planet to settle upon, the ruthless King Vega unleashes his armies—composed of flying saucers and giant robotic monsters—and turns first against neighbors such as Fleed, a highly advanced but peaceful world.

Too late, the only known survivor of the royal family, the Crown Prince Duke Fleed, manages to steal the Grendizer, the robotic embodiment of the Fleedian God of War, from the Vegan invaders who plan to use it to spearhead their invasion fleet.

Fleeing Vegan space by flying at faster than light speed, the Duke enters the Solar System and switches course to Earth, making a rough landing in Japan, on the slopes of Mount Fuji.

He is befriended by Doctor Umon, a noted scientist who oversees a research laboratory called the Space Science Lab near a small ranch.

The kindly Umon takes in the young humanoid alien as his son, under the assumed name of Daisuke, and assists him in hiding Grendizer.

Roughly two years later, Koji Kabuto, after studying abroad, returns to Japan in a flying saucer he personally designed and built, called the TFO.

Daisuke, however, scoffs at the notion and fears that these aliens, the Vegans, led by generals Blaki and Gandal, are preparing to attack Earth.

In order to save Koji and protect his adoptive homeworld from destruction, Daisuke is forced to return to his true identity as Duke Fleed.

Caught in a crossfire between Grendizer and a Vegan beast, he reveals to Maria that she is the last survivor of the royal family of Fleed (under the belief that Duke was killed) before dying from his wounds.

When Rubina discovers that planet Fleed is no longer polluted with Vegatron radiation and that her fiancé is alive and well, she rushes to Earth to bring him the good news.

It is also known as Space Disk War and was also released in Italy under the name UFO Robot Gattaiger-La grande battaglia dei dischi spaziali.

It was originally shown along with the short film Great Mazinger tai Getter Robot G: Kuchu Daigekitotsu, also from Toei and Nagai.

[citation needed] Nagai and Dynamic Productions created Grendizer using some of the elements and characters from Daiseno including Duke, the Makiba family, and even Blaki.

[citation needed] The series was first aired on Fuji TV from October 5, 1975, to February 27, 1977, replacing Great Mazinger in its initial timeslot.

It was produced by Gaina and directed by Shun Kudō with Mitsuo Fukuda serving as chief director, Nagai serving as executive producer, Ichirō Ōkouchi overseeing and writing series scripts alongside Tatsuto Higuchi, Yoshiyuki Sadamoto designing the characters, Kō Inaba, AF_KURO and Junichi Akutsu providing mechanical designs and Kohei Tanaka composing the music.

Like the Italian dub, it changed all of the characters’ names and inserted additional songs, although it did translate the series’ original opening and ending themes into French.

The show continues to have a strong following, garnering widespread news coverage of its DVD release and return to broadcast TV in Canada.

According to the creative team, Go Nagai himself gave his blessings to the comics story, which serves as a sequel to the original Toei anime set 10 years after the final episode.

Unlike most other Arabic dubs of anime, the show retained most of its plot details without any alteration or censorship in most Arabic-speaking markets, although some markets—such as Saudi Arabia and the UAE did censor certain scenes.

[35] Karim El Mufti, a professor of political science, said in his article about the anime, "UFO Robo Grendizer has surpassed the initial expectations of its producers.

As such, the domestication process of this character and of its whole narrative set was intimately connected to the Arab context and politics at the inception moment of the series, thus mirroring the deep preoccupations of the generations of that time.

High exposure to violence, aggression, and injustice in the Middle East had established a hospitable environment for the super-powerful resistance figure and pro-justice hero.