In 2063, space travel has become possible and commercially viable; a group of students from Caird High School departs to the nearby planet of McPa for their Planetary Camp.

Soon after the group arrives on the planet, the nine children encounter a mysterious and unforeseen intelligent sphere of light; it attacks them, transporting them into the distant depths of space.

To do so, they must cross the 5,012-light-year gulf of space separating them from home by visiting alien planets, the names of which are all anagrams, harboring life to replenish and manage their limited resources.

Astra Lost in Space, written and illustrated by Kenta Shinohara, was serialized on Shueisha's digital magazine app and website Shōnen Jump+ from May 9, 2016, to December 30, 2017.

After they forage enough food to leave Galem and Kanata has had some time to rest with Aries taking care of him, Charce tells everybody about the truth of Astra and Vixia.

However, when the plan was revealed to the public, war immediately broke out as different nations attempted to fight over land on Astra and the wormholes were misused as weapons.

Kanata has the Astra briefly stop above McPa so they can get into the communications system so Aries can send a message containing their entire story and pictures of the planets they visited to her "mother", Emma, who the group knows they can trust with instructions to contact a police officer that worked with Ulgar's brother.

As they return to Astra, they are greeted by a fleet of warships who welcome them home and inform them that their originals have been arrested for illegal cloning and attempted murder.

The man, who is the younger brother of the King of Vixia, responsible for Seira's assassination and the transfer of Aries to Team B5 is also arrested.