Arale and her friends from Penguin Village, after watching a movie that mentions Mechapolis, a mecha city, express a desire that it was real. That same night all the children get abducted and end up in the real Mechapolis! They learn that for that night every wish they have will be granted. What could possibly go wrong... (Source: M74)

Naoko-san is an alien from the planet Yuri, who is plotting to conquer the Earth by yurifying it. Misuzu is a junior high girl and is always troubled by Naoko-san, who lives on the roof of her house. They hear rumors that a molester is wandering around in the area, so they decide to investigate.

At the Penguin Village, the dinosaurs styled monster named Dodongadon appeared. But he was small as Arale and did not have strong power. Arale defeat him very easily, and Dodongadon called his mother Mamangadon. She was huge and had a big power. How Arale can defeat this big monster? (Source: Official Website)

Ten years ago, the villainous scientist Dr. Hell led his wicked followers, known as the Underground Empire, in a struggle to destroy all of humanity. It was against these forces that the young hero Kouji Kabuto fought, piloting the legendary super robot "Mazinger Z." Kouji's victory stopped Dr. Hell's evil plan and returned peace to the Earth. Now Kouji has left the pilot seat behind and become a scientist in his own right, following in his father's and grandfather's footsteps. Yet an unexpected encounter deep under Mt. Fuji triggers an even greater threat to mankind than ever before and alters Kouji's destiny forever. With humanity's fate in their hands, Kouji and Mazinger Z face a choice between good... and evil.