Kazumi and Noriko return to Earth for their high school graduation. Even though they are still teenagers after all these months in space, the Earth has aged ten years. Noriko meets up with her friend Kimiko, who now has a daughter. The Earth's forces discover that a massive number of alien spaceships are converging into the solar system. Coach has a strategy that involves creating a miniature black hole around Jupiter 2, but he will need Kazumi and Noriko to work together to pilot Gunbuster in order to put his plan into operation. However, Kazumi is having second thoughts as she's fallen in love with Coach and knows of his health situation.