High school student Aoba Watase lives an ordinary life in Tokyo. On his way to school, he is attacked by a giant robot that appears out of the sky. Eventually the enemy robot self-destructs, and Aoba loses consciousness. When Aoba wakes up, he finds himself 74 years into the future, where two nations are at war with each other. Aoba meets a boy named Dio Jyunyou Weinberg and together they would change the fate of the world.