The movie follows You, a high school student in modern-day Japan who dreams of becoming a musician but struggles with family opposition and conflicts within his band. One day, while walking through Shibuya, he hears a desperate voice calling for help, and a blinding white light engulfs him.

Meanwhile, far across the cosmos, the celestial body Meguriboshi is on the brink of war over the energy source known as "Hoshichi" (Star Blood). Just as a ceasefire is about to be negotiated between the warring nations, a massive orbital debris field 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.