During her childhood, Mira Kinohata encountered a star-gazing dreamer named Ao Manaka, who introduced her to the wonders of astronomy. Years later, while attending Hoshizaki Academy, Mira discovers that the Astronomy Club has merged with the Geology Club. Joining the newly formed Earth Sciences Club, she is pleasantly surprised to reunite with Ao. Together with their clubmates, Mira and Ao embark on a quest to fulfill a promise made long ago—to find an asteroid and name it after Ao.