In an ordinary town, an ordinary elementary school student Takamachi Nanoha (voiced by Yukari Tamura) who lives in a family of five lives a carefree life with her friends Tsukimura Suzuka (voiced by Ai Shimizu) and Alisa Barnes (voiced by Rie Kugimiya). One day, they accidentally discovered an animal similar to a mink, Yuno Scraia (played by Kaori Mizuhashi). The injured Yuno was rescued by Nanoha and others, but then various monsters appeared in the town one after another. With the help of Yuno, Nanoha used RisingHeart to transform into a magical girl, defeated the invading monster, and learned the secret of the energy crystal JewelSeed and her mission. In the days that followed, she practiced behind her friends' backs in order to become a qualified magical girl. That night, the mysterious magical girl Fate Testrosa (voiced by Nana Mizuki) suddenly appeared and fought fiercely with Nanoha. The long-standing relationship between them began...