Mazinger Z was already covered on this project, so today we get to focus on Devilman. In 1971, Go Nagai wrote and illustrated a horror manga called Demon Lord Dante about a student who is merged with the body of an ancient demon. Dante initially ended when the magazine it ran in, Bokura Magazine, was discontinued by the publisher, but Toei Animation approached Nagai for an anime adaptation which evolved into a new manga (and related anime) called Devilman.
Devilman (the manga, which ran in Weekly Shōnen Magazine) is the story of Akira Fudo, a teenager who learns of the existence of demons who are trapped in hibernation beneath the Earth and will invade soon. Akira is merged with Amon, the most powerful of these demons. As Devilman, Akira fights against the demons and wages an internal war of good vs evil as he struggles to control Amon.
In the anime (which began airing on July 8, 1972, several months before Mazinger Z), the demon invasion is still planned, and Devilman is sent to Earth, where he possesses the body of the recently deceased Akira Fudo. There he learns the meaning of love and rebels against his people, and becomes a transformation hero (who can grow to giant size) to fight the demons. Both versions were successful, and while the anime was significantly toned down from the manga to be more kid friendly, they're essentially alternate universe stories of each other. Both carry the trademark Go Nagai mix of hot-blooded protagonists, cool monsters, hot chicks, and hot chicks who are cool monsters.
Devilman aired for 39 episodes, and the franchise would see multiple manga down the line, as well as OVA miniseries, a spinoff series called Devilman Lady, a live action movie in 2004, and most recently the somewhat divisive Devilman Crybaby from 2018 (which aired on Netflix).
Which brings us up to speed for Mazinger Z vs. Devilman.
While fighting the robotic monsters of Dr. Hell, Koji Kabuto in the Mazinger Z and Sayaka Yumi in the Aphrodite A accidentally unleash the beautiful female demon Sirene from the earth. The demon flies away before anyone can do anything, but not before beeing seen by Akira Fudo, who turns into Devilman to chase after her.
Dr. Hell, seeing a potential ally, also follows, and frees a bunch of demons in the Himalayas. The two sides cut a deal. Dr. Hell will help defeat Devilman, and Sirene will help defeat Mazinger. Akira tries to warm Koji, but makes fun of Mazinger's inability to fly, so they get into a heated motorcycle race that ends in a tie.
Then the bad guys attack and Devilman rescues Mazinger, Mazinger rescues Devilman, and when the situation gets hopeless, Mazinger Z gets its major upgrade: the Jet Scrander. That's right, the Jet Scrander appears in this movie before its debut in the show. With the day saved, the two part as friends.
The movie is a fun bit of light entertainment that feels like a two-part episode with a higher animation budget. It doesn't exist in either show's continuity, instead acting as a kind of “what if” team up. It would, however, open the door for more crossovers between Dynamic Production series down the line.
Next time on Shin Super Robot Sunday: Toho goes green.