Mazinger Z, known briefly as Tranzor Z in the United States, is a Japanese super robot manga series written and illustrated by Go Nagai. The first manga version was serialized in Shueisha's Weekly Shōnen Jump from October 1972 to August 1973, and it later continued in Kodansha TV Magazine from October 1973 to September 1974. It was adapted into an anime television series which aired on Fuji TV from December 1972 to September 1974. A second manga series was released alongside the TV show, this one drawn by Gosaku Ota, which started and ended almost at the same time of the TV show. Mazinger Z has spawned several sequels and spinoff series, among them UFO Robot Grendizer and Mazinkaiser. It was a very popular cartoon in Mexico during the 1980s, where it was dubbed into Spanish directly from the Japanese version, keeping the Japanese character names and broadcasting all 92 episodes, unlike the version aired in the U.S.

Mazinger Z vs. Devilman is a 1973 animated movie that crossed over two then-popular Anime series, both of which were created by Manga artist Go Nagai. While fighting with some of his enemies Mazinger Z inadvertently knocks them into a volcano, where they crash into the prison of the Satan race and release Phoenix Jenny! Dr. Hell, learning of this, frees the rest of the Satan race and teams up with them to defeat Mazinger Z, and their ability to fly proves to be too much for our hero. Meanwhile, Devilman is also individually fighting the members of the Satan race, but their combined power is too much for him as well; can Mazinger and Devilman put aside their differences and team up to defeat Dr. Hell and the Satan race?

When a UFO arrives from space and attacks the Getter Institute, Getter Robo is launched to stop it; but the might of the UFO and its giant space monsters prove to be too much for the Getter team. Not only is Getter Robo defeated, but Ouishan is killed in action! With Getter Robo out of commission, the world's only hope appears to be Great Mazinger, but the aliens' power might also be too much for even him. Can Dr. Saotome build a new Getter Robo in time to help save Great Mazinger, Japan, and the entire world?

The story revolves around Duke Fleed who is a survivor of the Vega Star, raised by Dr. Umon as his adoptive son, and known as Daisuke Umon on Earth. Years after his arrival, he's faced with the threat of King Vega and his army, who want to conquer the Earth. With his friends Koji and Hikaru (and later his kid sister Maria Grace), Duke decides to fight back using his best weapon, the almighty Grendizer.

It is the year 2074. In a world threatened by aliens... an unlikely hero emerges! Ken Izumi may look like an ordinary 10-year-old boy, but he secretly possesses weapons, armor, and accessories that transform him into the superheroic Chargeman Ken. Ken protects his mom, dad, little sister Caron, robot pal Barican, and the rest of mankind from the diabolical Juralians, shape-shifting alien invaders bent on terrorizing the earth. The only thing standing between the fragile human race and conquest by the Juralians is Chargeman Ken and his unquenchable thirst for fiery, atomic justice!

Devilman features Akira Fudo, a shy and timid teenager who has gone mountain climbing in the Himalayas with his father. While in the middle of the expedition, both father and son are killed in a tragic accident. Akira's body is found and possessed by the demon soldier Devilman, who uses his new human form as a disguise in order to fulfill his mission of causing chaos on Earth in order to pave the way for a demonic invasion of the planet.

Before his mission can begin in earnest, Devilman meets Akira's childhood friend Miki Makimura and quickly falls in love with her. Devilman resolves to protect Miki and humanity as a whole by battling against his fellow demons. Demon Tribe leader Zennon becomes greatly angered at Devilman's betrayal and is quick to send Devilman's former comrades to destroy him. The other demons soon learn that Miki is precious to Devilman and he must now work to protect her, as well as protect himself. Will the power of love be able to overcome that of true evil?