Ryota and the other students travel to the Aries Station. Aya arrives at the spaceport. As they settle in, Ryota receives a message that his brother is coming for a visit.
Shuhei, Aki and Aya arrive on the station. During their first training simulation, Ryota buys time for Sayaka to find Aya and tell that she will not be able to see each other. After the training, warning klaxons signal an emergency.
Terrorists begin their attack while the crew and passengers attempt to evacuate.
Some are stranded on the station. Shuhei and Cellaria are injured in battle. Flashback to Nao's childhood.
Flashback to Aki's childhood. The military students prepare for a counter-assault on the terrorists.
Cellaria is captured. Shuhei attempts a rescue.
Discovery of a strange virus. Cooperation occurs all over the station for survival. Nao is injured in an attack.
Nanami is found. The terrorists are double-crossed. Flashback to Yu's childhood.
Shuhei is being corrupted. Yu is captured but escapes with the help of her childhood friend.
Cellaria's past is revealed. The military students make plans to leave the station.
(Special Recap Episode)
Special recapCellaria's background story, and Nanami's background story. This episode is not included in the count of total number of episodes.
Aya manages to escape at the cost of Gale's life who ensures her safety.
With the station starting to burn up in the atmosphere of Earth, the rest of the crew commence the evacuation of the station. The events shift forward for 1 year, where everyone returns to their normal lives. Most characters' futures are revealed as well.