As technological progress continued, humanity expanded its reach across the vast expanse of the solar system, setting up colonies on every planet from Mercury to Pluto. This led to the creation of a massive athletic tournament known as the "Daiundoukai," where aspiring female athletes from all corners of the solar system come together to compete for the title of "Cosmo Beauty," a designation that grants queenly prestige. Kanata Akehoshi, a spirited potato farmer, recalls a pivotal moment from her childhood: she witnessed a glowing object plummet from the sky, crashing in a nearby forest. Eager to investigate, she stumbled upon a damaged spacecraft and a weakened girl who bestowed upon her two wristbands, along with a plea to participate in the Daiundoukai and become the Cosmo Beauty. Kanata accepted the invitation, but before she could learn the girl's name, she vanished without a trace, leaving behind only the wreckage from the crash. From then on, Kanata devoted herself to training, driven by a sense of obligation to fulfill her promise. After earning her spot as the representative from planet Earth, Kanata journeys to the University Satellite, a specialized institution where competitors train and prepare for the upcoming tournament. There, she connects with her fellow athletes, fostering a sense of camaraderie and cooperation that will aid them in the upcoming games. As Kanata draws nearer to the lofty title of Cosmo Beauty, she also draws closer to the enigmatic girl who had such a profound impact on her life. Along the way, she uncovers a mystery hidden at the heart of the Daiundoukai, a discovery that adds another layer of complexity to her already high-stakes mission.