Tegami Bachi 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. He is entrusted with the "hearts" of everyone in AmberGround to deliver their packages.