In a future where humanity has expanded across the solar system, an athletic tournament known as the 'Daiundoukai' gathers ambitious female athletes from various planets. Kanata Akehoshi, a former potato farmer, receives a mysterious request from a girl she once encountered after a spaceship crash. Entrusted with special wristbands, Kanata ventures into the tournament to become the revered 'Cosmo Beauty.' As she trains and competes, Kanata forms bonds with her competitors, uncovering secrets about the competition and inching closer to the enigmatic girl from her past.