Tegami Bachi

The story takes place in the land of AmberGround, a place of perpetual night only partially illuminated by an artificial sun. Lag Seeing works as a "Letter Bee" (delivery boy) at the "Bee Hive" (a delivery service), with his Dingo, Niche, and her "pet", Steak, traveling with him. As a Letter Bee, Lag's job is entrusted to deliver letters and packages from town to town while avoiding Amberground's deadliest hazard — a species of giant armored insect known as Gaichuu, who attempt to feed off the "heart" that reside within these letters and packages (Source: TV Tokyo)