Children who chase lost voices from deep below (Blu Ray) - Anime

Life hasn't been easy for Asuna since the death of her father. With her mother forced to work long hours to make ends meet, Asuna spends most of her time alone, listening to the crystal radio her father left behind. It's a curious thing, requiring neither electricity nor an amplifier, but the strange music that plays over it is an even greater mystery. Where does it come from? And what does it mean? The answers will lead Asuna into a hidden world filled with incredible dangers, where monsters roam and even the dead can be brought back to life. But there's a price that comes with unlocking the secrets, and it may be more than Asuna can afford to pay!