The boy Fig Kamura, who was fighting as a NATO soldier on Earth in 2035, suddenly moves to another world. It was Xanadu, a world where peaceful white magic and black magic for battle compete. Fig has no memory of the past, but rescues Riel, the princess of the Xanadu dynasty, who is attacked by a black magic monster. While the king is murdered by Lake Sor, a man who manipulates black magic, and Crystal, one of the three treasures, is robbed, Fig and Riel learn from Archbishop Tuston about one of the treasures, the Holy Sword Dragon Slayer. The next target for Lake Sor, who is trying to achieve his ambitions by abusing crystals, is Riel's treasure, Chrysoberyl. Can Figu rescue the captured Riel?