The Familiar of Zero: "Rondo" of Princesses

Saito's runes disappear before his, Louise's and Siesta's eyes. While on a trip to the castle, they are attacked by Sheffield, who is revealed to be the familiar of an unseen Void mage that she refers to as "Master Joseph". After arriving at the castle, Saito is given a paper by the princess that would make him a knight and effectively a noble. He, however, turns it down on the issue that he does not believe he can protect the princess or Lousie without the familiar's contract. When asked about the disappearing runes, he tells them about the elf, whom he recalls as Tiffania. Derflinger tells them where they may find her so Louise and Saito prepare to depart. That night while worrying about recent events, Louise awakens to find Saito awake outside on the balcony. She tells him that she is afraid of him leaving again, especially with the disappearance of the runes.

While they are traveling to the village where Tiffannia is living, they meet up with Siesta who is carrying cooking supplies and food. At the same evening, while they were having dinner, Louise gets into another fight with Saito and walks off. Agnes, who was making a wooden sword, asked Saito to train a little bit. The next morning while they are traveling, Saito sees Tiffania and chases after her. At first she doesn't recognize Saito but after shouting her name a few times, she turns around and hugs him. Louise and Siesta are jealous when they see how big Tifannia's breasts are. The same evening Louise tries to ask who she is, and Saito explains that she saved him during his battle. Out of spite, Louise starts to fondle Tifannia's breasts. But when Saito stops her, Louise runs away and Siesta follows her. After forming a temporary alliance against Tiffania, the two get attacked by Sheffield.

Tiffania travels back to Tristain with the group. While introducing herself to the Queen, she forced to remove her hat revealing a pair of long, pointed elf ears. Elves are shunned by civilized society, and she explains that she is in fact a half-elf. Her mother was an elf that passed away years earlier, and her father was the archduke of Albion and Henrietta's uncle. As the Queen, Saito, Louise, Agnes, and Tiffania discuss the whereabouts of the other void user(s), Henrietta offers to knight Saito again and he accepts. Henrietta also appoints Siesta as Saito's servant, much to Louise's frustration. Saito, Louise, and Siesta arrive back at the academy by dragon to a huge celebration in Saito's honor lead by the self-proclaimed Knights of Ondine, a group of students at the academy captained by Guiche.

Saito begins training daily with the Knights of Ordine. This leads to him not having as much time to spend with Louise, arousing her jealousy once again. Matters only become worse when Tiffania shows up as a transfer student at the academy. A student named Beatrice, whom is revealed as royalty, becomes suspicious of Tiffania when she refuses to remove her hat. After telling her that she will remove the hat eventually, Tiffania decides to reveal her true identity as a half elf. Upon the revelation, Beatrice proclaims that she has the authority of the Pope and insist that Tiffania be put through a heretical interrogation. She proclaims that if Tiffania believes in the true god, she will be able to step into a pot of boiling water she has had prepared. Saito shows to stop her, but upon hearing from Guiche that Louise would be in trouble he interferes, he bows a begs Beatrice to stop.

After the events of the last episode, Saito was forced, in his boxers, to read aloud and sign a pledge admitting that he took advantage of Tiffania in the infirmary. However, he refuses to sign it, insisting that it was she who asked him, and leaves. Upon seeing the shack where Professor Colbert kept his books and other materials, he entered and sadly remembered the teacher's wish to someday visit Saito's world. He apparently starts to doze off, but wakes up after hitting his head on the table. His attention then turns to the piles of gifts being left for Guiche and Reynald, and inquires as to their meaning, in which case, Reynald explains that gifts from the ladies are becoming more common after the fight with the Air Dragon Knights from the previous episode. With love seemingly in the air, Saito remembers the fight with Louise and becomes rather depressed. Upon seeing this, Guiche, Malicorne, and Reynald grow determined to cheer him up.

It starts off with Siesta at the imp cafe with her uncle and cousin, Jessica, telling her to try harder at getting Saito, eventually giving her a love potion. After the credits, it goes to Saito and Louise’s room where Siesta is cleaning and contemplating using the potion on Saito when Louise comes in dragging Saito who is tied up behind. This causes a fight between Louise and Siesta about the treatment of Saito. Finally, Siesta who believes that she can take better care of Saito than Louise is allowed one hour for that purpose.

Siesta, in an effort to win Saito, challenges Louise to a contest. If he can locate Louise at the Seipnir ball, she will relinquish her advances towards him. Louise accepts, telling Saito that if he succeeds, she will allow him to “continue what he started before”. The ball arrives, and each participant takes a turn at the mirror of truth, which transforms him or her into their ideal self. Saito, on the way to the ball, notices a dark shape flying over the academy. Believing Louise to be in danger, he rushes in and begins to search for her. Locating her on the balcony, he has a brief conversation with her before the two kiss. Sheffield then arrives and disrupts the ball, destroying the mirror and reverting everyone to their former selves. Saito then discovers that the girl he kissed is not Louise, but is in fact Princess Henrietta, who had taken Louise's form.

Colbert is alive. He was saved by Tabitha before death. Using knowledge from the dragons plumage he constructed an air ship with an advanced engine. Louise is still suspicious about what she witnessed between Henrietta and Saito and enlists the help of Siesta and Tiffania to capture Saito and force him (by using magic) to reveal what happened the previous night. Pursed across the ship (under the mistaken impression the magic will remove his clothes) by the increasingly desperate trio he is finally cornered and it is revealed to all about Tabitha's involvement in the previous nights escapade. Saito and Henrietta have difficulty meeting each others eyes throughout the episode but the episode concludes with Louise's resolution to trust Saito while Siesta is still concerned.

A nude girl falls from the sky and introduces herself as Tabitha's younger sister. Is she really who she says she it?

Saito and company take refugee in the Charming Fairy Inn while the search for them continues. A plan is created to use the Ostland to fly towards Germinia as a decoy, while Saito goes across the border directly. Scarron provides disguises for them, while Colbert, Seista, Gimli and Reinard proceed to liberate the Ostland. Siesta shows doubts at first of not having any powers but gets encouraged by Saito that she could still help. She hugs him so Louise kicks him in the groin from behind. In Gallia, Joseph and Sheffield uncover a massive object, which Joseph calls Jormungand, covered with pulsing veins and with a single large eye. Posing as a travelling circus, Saito and company cross the border, while Louise broods over no longer being an aristocrat, realising she only has Saito left. Back at the castle, using Siesta as a distraction, Gimli and Reinard take out two guards and they board the Ostland, after dispatching two more groups of guards.

Using her talents at persuasion, Kirche discovers that Tabitha is being held in Al Hambra. Upon arriving there, the gang decide upon a plan of attack.

Louise has a nightmare in which she loses the ability to cast magic; waking up, she finds that her nightmare has come true. In Tristain, Henrietta dispatches the Ostland and Colbert to rendezvous with Saito, carrying a type of cannon and Agnès offers the assistance of the Musketeer Corps. Saito, under Tabitha's guidance, learns to read quickly, while Louise broods over her inability to cast magic. Overhearing Tabitha telling Saito that under the influence of Gandálfr, the heart will experience changes, Louise wonders if Saito loves her because of Gandálfr's influence. Louise is captured. Guiche, Kirche, and Tabitha's attacks prove ineffective against an attacking golem. Louise decides to sacrifice herself for her friends.