This sequel to the Silent Mobius The Movie 1 continues the timeline of the flashback section of the first movie (Katsumis initial contact with AMP), using some more ideas and persons from the Manga, and being slightly less incompatible to the Silent Mobius series from 1998.

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.

Five female pirates pilot the Sol Bianca, a starship with a higher level of technology than any other known. With it, they seek out riches, such as the Gnosis, an legendary item of power, and pasha, the most valuable mineral in the galaxy. Along the way, they must consider a stowaway's quest to save the one he loves, and seek revenge against those that have wronged them.