Magical Girl Lyrical Nanoha StrikerS (魔法少女リリカルなのはStrikerS, Mahō Shōjo Ririkaru Nanoha Sutoraikāzu?) is the third season of the Magical Girl Lyrical Nanoha series. The Nanoha anime was, in turn, a spin-off of the Triangle Heart series of games and OVAs, specifically Triangle Heart 3: Sweet Songs Forever. This season aired shortly after the promotional event "Lyrical Party III" scheduled on April 1, 2007.
StrikerS takes place after the epilogue of Magical Girl Lyrical Nanoha A's, aired between October and December 2005. While the epilogue connected A's to a world six years later, StrikerS advances the timeline another four years, where the main characters have gone on to work for the Time-Space Administration Bureau (TSAB) and come upon a new case. The series focuses more on team-based battles and bureaucracy rather than individual rivalry and school life, due to the change in character dynamics.
A special sound stage, under the name of StrikerS Sound stage X will be released in Autumn 2008 on October 29. The story takes place 3 years after the events of StrikerS and continues the story of the 4 recruits of Section 6: Subaru, Teana, Erio and Caro, along with Vivio and the rest of the other Numbers.