Season 1: The show tells us about Takamachi Nanoha a 3rd grader elementary school girl. One day Nanoha hears a voice calling for which only she could hear, the voice belonged to Yuuno Scraia a mage from another world who came to this world to collect and seal the "Jewel Seeds". Yuuno was injured during a battle and had to take the form of a ferret. When Nanoha finds him he tells her about his mission and gives her a special device to help her use her powers. Nanoha decides to help Yuuno to collect the seeds and they go together to adventures while collecting the "Jewel Seeds". But, quickly another mage called Fate Testarossa comes also to collect the "Jewel Seeds". Will Nanoha win and find and collect all of the "Jewel Seeds"? Will she be able to defeat Fate?
Season 2 - Magical Girl Lyrical Nanoha A's: Several months after Nanoha first became a Magical Girl, she still is unable to personally meet with her new close friend, Fate Testarossa, who is being tried in the Space / Time Administration Bureau for her association in the Lost Logia case. They still communicate through video-mail and hope to see each other in-person once again. Their reunion is not a happy one, unfortunately, as several people who call themselves "Velka-Type Knights" battle Nanoha above the city. Their objective is to fill the pages of the Book of Darkness by stealing the magical power of anyone they can find. Nanoha and Fate must once again team up to stop their plans and save the world.
Season 3 - Magical Girl Lyrical Nanoha StrikerS: Set 10 years after the events in Lyrical Nanoha A's, now three Rank S mages, Nanoha, Fate and Hayate are working for the Time-Space Administration Bureau. Following Hayate's dream to make her own division that helps into all kind of disasters, including the Lost Logia cases, Fate and Nanoha including their own trainees, create the 6th Mobile Division. Unfortunately not all can go as planned, because uncontrolled Lost Logia will get in the way of the 6th Mobile Division and is up to Nanoha, Fate and Hayate to deal with them while training their new trainees and helping with other tasks that arise along the way.moreless