The story begins with 18-year-old Gauche Suede, a Letter Bee, arriving to pick up his latest package. However, he was surprised to find his letter to be a little boy named Lag Seeing. Lag has just lost his mother, who has been taken to Akatsuki, AmberGround's capital, and the boy is to be delivered to his aunt's residence in Campbell Litus. Along the way, the Letter Bee tells the boy briefly about his job and the Gaichuu he has to repel. After a mishap regarding Lag unwittingly firing Gauche's weapon, the Shindanjuu, Gauche takes the boy to a cave to rest for the night. After Lag has recurring dreams regarding Gauche's lifestyle and his sister Sylvette, the boy wakes up to discover Gauche and his Dingo Roda lying exhausted from a fight with numerous Gaichuu.