Memory Eaters

Memory eaters live on people's memories. They are originally death messengers who remove a human's memories when they carry souls. But some of them are charmed by the beauty of the memories and become Exiles. Dio is one of them, but instead of stealing human memories like other Exiles, he earns them by helping people. One day, Dio finds a girl who is losing too many memories from Exiles. He tries to help her, but Ces, who was a model death messenger, is around her. What is he doing here?