In the Kingdom of Solis, locked in eternal winter, only a marriage between a pure-blooded princess and a dark dragon can restore the sun's warmth. Princess Diana grew up happily with her three brothers—until Lorelei arrived. Using stolen dragon scales, Lorelei seized all of Diana's love and standing. Deceived, her three brothers cast Diana out, even offering her as a sacrifice to slay the dragon. After the dragon carries Diana away, the truth comes to light. But by then, it is already too late.