Mistarcia is a magical world where humans, gods, and demons mingle together. In the past, the black-and-silver winged Bahamut has threatened to destroy the land, but humans, gods, and demons overcame their differences to fight together and seal its power. The key to that seal was split in two, one half given to the gods and the other to demons, so that they would never be united and Bahamut never released. Now, two thousand years later, the world is in an era of peace - until the day a human woman steals the gods' half of the key.
Mugaro is a mysterious boy sought by both the king's Onyx Task Force and the gods. He possesses a power that is feared by the former and needed by the latter. Who is this child and where did he come from? Only time will tell.