Set in the 22nd century, where space travel, planetary colonization, and anti-gravity basketball are ordinary parts of daily life. Earth has become impossible to live on, so people reside in colonies on neighboring planets. During a school field trip, a mishap sends the protagonist—a new transfer student named Luna—along with her pet robot and six classmates hurtling through a gravity storm. They crash land on a planet that appears deserted. With Luna taking charge, the group—including the robotic cat Chako, the independent Kaoru, the pampered rich boy Howard, the timid Sharla, the compliant Bell, the proud musician Menori, and the young genius Shingo—must struggle to survive. Yet is this world truly empty, or does something—or someone—lurk in the shadows, waiting?