Six months following the events of the previous series, Nanoha Takamachi and Fate Testarossa have been exchanging video mails to tell each other of their situations on Earth and in the Time-Space Administration Bureau respectively.

However, on the night Fate returns, Nanoha and her friends come into conflict with the Belkan Knights, Signum, Vita, Zafira, and Shamal, who are tasked with filling the pages of the Book of Darkness to protect their master, a wheelchair-using girl named Hayate Yagami.

A manga adaptation of the story was serialized in Gakken's Megami Magazine between August 2005 and January 2006 issues and was released in a single volume on February 18, 2006.

[5][6] Magical Girl Lyrical Nanoha A's was later licensed by Geneon for English-language dubbed release in the United States and Canada.

[8] A series of three drama CDs have been released by King Records between November 23, 2005, and March 8, 2006, entitled Magical Girl Lyrical Nanoha Sound Stage 01~03.

[14] "Super Generation" was released on January 18, 2006, that contained the track "Brave Phoenix", which was used as an insert to episode twelve of anime series.

A second game, Magical Girl Lyrical Nanoha A's Portable: The Gears of Destiny, was released on December 22, 2011, and features additional characters from the ViVid and Force manga series.