Mahou Shoujo Lyrical Nanoha A's

Synopsis

Although the danger is averted, the potential for the corruption to return remains, and Reinforce gives up her existence in order to prevent that. Hayate and the Wolkenritter join the TSAB, and Nanoha tells her family about what she has been doing as a mage. Six years later, Nanoha, Fate and Hayate are in middle school, with Hayate having a second Reinforce by her side.

(Source: Wikipedia)