The Familiar of Zero Knight of the Twin Moons, Japanese anime tv series 2007

Story:

Louise the Zero and her familiar Saito are back for another round of chaotic magic and even more chaotic romance. With the Albion invasion put to a stop, it seems as if peace has finally returned to the Kingdom of Tristain. After Saito sacrifices his only chance to return to Tokyo in order to remain at Louise’s side, it seems like the relationship between this fiery mage and her familiar should finally find a little peace as well. Unfortunately, thanks to Saito’s wandering eye and Louise’s explosive temper, their relationship is more turbulent than ever. As Louise struggles between understanding her feelings for Saito and her powers as the only Void magic user in the world, the threat of war looms once again on the horizon with the appearance of a dangerous foe wielding a dark artifact. With Louise’s childhood friend Henrietta now crowned Queen of Tristain, Louise will have to learn to control her magic if she hopes to protect her friend and put an end to the conflict once and for all! (story from Sentai Filmworks)

External Link: Official Website