In 2199 AD, the Gamilas Empire, an enemy from outside the solar system, began to invade other planets in order to save its home planet from danger. The Earth Army was defeated in the battle with the Gamilas Empire Army, and at the same time, the Gamilas Empire Army launched a large number of radioactive planetary bombs at the Earth. The Earth's resistance is getting weaker and weaker. Iskandar, a twin planet with Gamilas, came to the rescue and sent the design drawings of the wave engine and wave gun to the Earth, and informed the Earth Army that the planet has the equipment "Space Cleaner D" to remove radioactive energy. After losing contact with Europe and America, the Earth Defense Force used the technology provided by Iskandar Planet to transform the Yamato sleeping on the seabed into a space battleship. All the crew members of the Yamato embarked on a long journey to retrieve the "Space Cleaner D".