The film centers on You, a high school student in contemporary Japan who aspires to become a musician but faces resistance from his family and friction within his band. One day, while strolling through Shibuya, he hears a desperate cry for help, and a blinding white light engulfs him. Meanwhile, far across the cosmos, the celestial body Meguriboshi stands on the brink of war over an energy source known as "Hoshichi" (Star Blood). Just as a ceasefire is about to be negotiated between the warring nations, a massive field of orbital debris descends, threatening disaster. Laco, a young mechanic, rushes to aid the planet's defense force but finds herself in grave danger. As she falls into unconsciousness, her mind connects with You's, marking the beginning of their intertwined fates.