Tegami Bachi: Letter Bee (2009)

In a dark land of near-perpetual night, only a single artificial sun illuminates a single city, and communication between the rest of the world is made possible only by the Letter Bees - elite couriers who must fight against monsters known as Gaichuu in order to make their deliveries. Having been saved by a Letter Bee when his mother was kidnapped years ago, Lag Seeing has finally gained employment at the Bee-hive, but he's quickly learning that the dangerous job has become even more lethal, with renegade humans now targeting the Letter Bees as well. Fortunately, Lag's been blessed with the ability to see into the memories of others, and every Bee is also supposed to find a "Dingo," a partner to watch their back. However, when Lag finally finds his Dingo, she's not at all what he expected. In fact, she may end up being the girl who kicks over the entire hornet's nest. But no matter what the stings of fate, Lag isn't going to let anything clip his wings.