Tegami Bachi(aka Letter Bee)is set in the fictional land called "AmberGround", where an artificial sun only illuminates the capital of the land, Akatsuki. The story follows Lag Seeing, a young letter bee and his personal dingo, Niche, on their journeys around the AmberGround. Lag's job is to deliver letters and packages from town to town while avoiding Amberground's deadliest hazard — a species of giant armored insects known as Gaichuus. He has a special ability to see the memories of people and items when his Shindanjuu is fired at them.

Source:Wikipedia