Larc, Pasica, and the others are called to guard the excavation of Saturn's moon Titan, which is in the process of excavating ruins rumored to be an alien buster machine. However, Nono is not accepted as his companion and is forced to do chores every day. Nono, who believes that he will be recognized as a full-fledged person if he has his own Buster Machine, invades the excavation site alone.