October 1941. With the Second World War threatening to destroy the civilized world, an unforeseen complication arises: an alien invasion. Despite the sudden appearance of extraterrestrial aggressors, the Axis and Allies continue their destructive conflict. Only the Kishin Corps and their giant Geo‑Armor Robots, developed from a captured alien robot soldier, stand between Earth and total annihilation. A teenager named Taishi suddenly finds himself at the center of a struggle over a mysterious black attaché case entrusted to him by his father, Professor Tokamura. The case contains the control mechanism for one of the giant Geo‑Armor Robots, and the Japanese Kanto Army, …