Centuries ago, Kanna, a princess and the last of a winged race, was held prisoner in a castle as she was feared by the rest of the world. However, when she met a soldier named Ryuuya, she fell in love with him and told him of her wishes to see the outside world and to find her mother. Ryuuya attempted to fulfill these wishes. However, his efforts were in vain as Kanna was sealed in the sky through magic and cursed to be in pain for all eternity.