S2.E9 ∙ Sakamichi no tochû

In 1932, the Japanese Army investigates a mysterious meteorite crash in Manchuria, and discovers a strange material that produces a previously unknown kind of energy. The mineral is later used during the Second World War to power a massive submersible battleship Ra, which is built to revitalize the war effort. Shortly before the launch, a young woman named Annette approaches the officers of the Ra and implores them not to use the battlesub. She says the material was sent by subterranean humans to test the surface dwellers right to live, and by using it as a weapon of war they are sealing the human race's fate. The Ra is launched in the twilight days of the war, and shortly after the bombing of Hiroshima the Ra encounters the American battlesub Liberty, whose crew has been tricked into fighting the Ra by Annette's former partner and friend Avatar, whose appraisal of the human race is much more negative than her counterpart. Annette stops Avatar with a blast of mental energy, but the Ra and Liberty destroy each other. Annette and the Ra's first officer are the only survivors. Fifty years later, an unaged Annette and the grandson of the Ra's captain, Go Arisake, are part of a UN team sent to investigate microwaves being generated at the South Pole. It proves to be a prelude to a massive attack from below the Earth, led by Avatar, that will culminate in the complete destruction of the surface humans. However, Go discovers his grandfather's old ship has been found and rebuild as humanity's last line of the defense, commanded by his believed to be dead father, as the final battle to defend Earth begins.

The Japanese AEGIS Destroyer "Mirai" of the Japanese Maritime Self Defense Force is on its way to Pearl Harbor for training missions when it's suddenly engulfed in a strange electrical storm.

During the Age of Warring States, the upcoming warlord Sasuke Furuta is torn between his political ambition and his love of the tea ceremony.

In 1983, the East German Army 666th TSF Squadron "Swarzesmarken" are fighting on the front lines against the alien invaders known as the BETA.

In this continuation of the previous season, not long after the war, Louise and Saito seemingly getting along now since she knows that he had given up his only chance to return to Tokyo for her. The story continues as Louise begins to use Void Magic from a mysterious secret book she had received from her majesty Henrietta, while a new villain has appeared in town causing trouble.

Young Lundi finds an amnesiac girl, names her Jeudi. A Count kidnaps her, mistaking her for a past love. Lundi rescues Jeudi and they seek her identity, aided by Leonhardt, while evading the Count and Nazis during WWII.