Manga adaptation of Jetter Mars, a 1977 anime produced as the successor to Astro Boy.

The year is 2015. Dr. Yamanoue, Director General of the Ministry of Science, creates a boy robot named Mars as the most powerful weapon to protect Japan. However, he is unable to develop the best cyber brain he needs, so he asks his rival, Dr. Kawashimo, who disagrees with him, to develop it for him. After incorporating it, Mars is finally completed, but Dr. Kawashimo's anger is aroused because Yamanoue had concealed the fact that Mars is a weapon. Mars himself, on the other hand, has just been born and knows nothing about the world or common sense, and is unable to distinguish between right and wrong.