"Astronomy + Geology" is more fun than expected? A girl's quest to keep a promise made in her childhood begins with finding an asteroid! Mira made a promise with a boy she met at a camping site during her childhood to go on an "asteroid hunt." She wanted to join the astronomy club in high school, but this year, the "astronomy club" and the "geology research group" are merging to form the "geoscience club"?! This is the story of their adventure to find the promised asteroid together.