Tegami Bachi is set in the world of Amberground, a land where dozens of diverse and scattered towns are connected by the Letter Bees, an elite cadre of men and women who deliver letters, packages, and occasionally even people from town to town.
The principal story drives along the escapades of Lag Seeing, a rookie Letter Bee (and former Letter) as he seeks out Gauche Suede, the Bee, who saved him after his mother disappeared... and who has since disappeared into himself. With his Dingo, a somewhat... unusual young lady by the name of Niche, Lag delivers letters, battles Gaichuu, hunts for the missing Gauche, and slowly but surely begins to find himself drawn into a hidden conflict that threatens to rip apart the already troubled land of Amberground.