As she roamed, Takamachi Nanoha, a third-grader, heard a telepathic plea for aid and discovered an injured talking ferret named Yuuno. Yuuno was an archaeologist and magician from another realm who accidentally spread hazardous Jewel Seeds on Earth. However, he was too frail to retrieve them himself and had converted himself into a ferret. He entrusted Nanoha with this task, providing her with a red jewel that would enable her to metamorphose and employ magic to combat the monsters that were threatening their world as a result of the Jewel Seeds. Nonetheless, the danger persists since others are also hunting for these potent relics.