Year 2124, Christopher is on research expedition on Mars but he discover a missing commercial vessel...

Recap of the first season of Hitori no Shita: The Outcast that aired a week prior to Japanese broadcast of the second season.

While the young Angelique lives out her days peacefully in her school, attacks from the monstrous Thanatos has been increasing everywhere else. Two Purifiers show up one day, men with the power to exterminate the Thanatos. One of them, Nyx, attempts to convince Angelique to join them in their work, as she has the power to be the only female Purifier. As Angelique hesitates, a Thanatos shows up in their school. Nyx and the other Purifier, Rayne, fight a losing battle. With her classmates falling prey to the Thanatos, and the Purifiers beaten to submission, Angelique's desire to save everyone awakens. She became the only female Purifier in their land of Arcadia, the one known as the "Queen's Egg".

Dreaming of a magical world every night, the young Toramizu Ginta yearns to be able to go there. With only his friend Koyuki believing in his dreams, Ginta remains positive despite the slander he receives from others over his dreams. But his wishes are answered, as one day a large door appears in front of Ginta, summoning him to the land of MAR Heaven. In this land, the weapons known as ARMS exist. While initially Ginta greatly enjoyed the discovery of this magical world, he soon learns of the terrible wars that have once plagued MAR Heaven and the upcoming war that may soon appear.