In 2199 AD, after obtaining the Cosmo Reverse System on Iscandar, the Space Battleship Yamato prepares to depart from the Large Magellanic Cloud galaxy. On the galaxy's edge, they unexpectedly encounter a mysterious group called the "Gatlantis," led by Goran Dagaamu of Thunder, commander of the Gutaba expeditionary force. Dagaamu demands that the Yamato be handed over to him. Despite their eagerness to return to Earth, the Yamato tries to avoid conflict but is struck by the formidable "Flame Direct Attack Cannon," a weapon capable of penetrating space itself. Though hit, the Yamato escapes but finds itself lost in an irregular dimension of strange colors. The crew decides to shut down the engines and investigate a mysterious planet. To gather information, Kodai, Kiryū, Sawamura, Niimi, and Aihara land on this planet. Upon arrival, they discover a ship that should not be there. Dagaamu, following the Yamato's jump trail, also arrives in this oddly colored space. The planet where the Yamato has landed is precisely the place Dagaamu has been searching for.