Sadamitsu, a high-school delinguents turned to a masked-hero, while not dealing with his rocky relationship with the strong female protagonist, he puts on a motorcycle-helmet-like mask and becomes a semi-robotic superhero who fights. He is assisted by other possibly- mechanical creatures in order to save the earth from the invasion of 20,000,000 escaped alien convicts.

Astro Boy appears to be a normal, playful kid, yet he is a robot capable of both flying and incredible strength. Living with his parents in a small town where humans and robots coexist, he has many friends thanks to his cheerful nature. Eager to learn and try new things, Astro and his companions often embark on exciting adventures. But their explorations are met with unexpected troubles when the wicked criminal Hamegg—joined by his accomplices Gora, a pink gorilla robot, and Professor Flau—interferes with their endeavors. As the little robot boy and his group bravely face challenges, their efforts become part of a journey to discover the world's values and wonders.

Thousands of years into the future, mankind has colonized other planets across the galaxy and completely forgotten about Earth. On one part of the galaxy, the female space pirates and their colossal starship Sol Bianca get a surprise when a young girl named Mayo stows away on board the ship. The crew then embarks on a journey to Earth to find the whereabouts of Mayo's parents and discover the secrets of the lost planet.

Yumi Ikoma and Ryou Masaoka are children who have been selected to take part in a top secret mission, to be the pilots of the first Fafner combat units; the last chance of survival for the human race. The enemy is ruthless, remorseless and is able to read the minds of humans. Therefore, the details of this mission are kept a secret even from the personnel involved. The young pilots must use all their courage and faith in order to survive and complete their mission or the fate of mankind would be compromised.