In a brief flashback, the main character Luna is shown as a young girl being pushed into an escape capsule by her father, who is then killed in an explosion. Several years later, Luna is preparing for her first day at a school she is transferring into. Upon entering the grounds, she is stopped and scolded by the student council president Menori for running on the pavement, but quickly befriends a kinder girl named Sharla. On their way to class, the girls run into a student named Howard and his gang taunting an older boy from Pluto named Bell, telling him to clean their shoes better. Luna attempts to intervene, only to be told that Bell in fact wants to clean their shoes. At the start of class, Luna is introduced, as is another recent transfer student named Shingo. The teacher discusses a field trip coming up, meant to give the students experience in planetary settling, and some of Earth's late history is revealed. During gym class, Luna, Sharla and another student named Kaoru play Air Basketball against Howard and two others. Luna scores with some help from Kaoru, despite Howard playing rough. On the way home, Shingo nearly hits the girls on a gasoline-powered scooter he has built. While discussing the scooter, they hear Howard and his gang starting a fight with Kaoru. Luna tries to stop the fight, but a member of Howard's gang accidentally starts a fire. Howard and his gang retreats, but Sharla is trapped by the fire.