The Familiar of Zero

Saito and Osmond come across a chest from Earth filled with bikinis. After examining the treasure trove, Osmond decrees that the students will take a trip to the beach! While there Osmond instructs the girls to change into various kinds of bathing suits and partake in other “rituals” pertaining to a beach outing.

Despite being from a famous magic family, Louise has never been able to successfully cast a single spell. On the day of her familiar summoning exam, she bungles the summoning and accidentally summons a human from Earth. The poor victim of her mistake is Saito Hiraga, a typical high school boy.

An abrupt departure from the normal life he once lead, Saito must deal with being Louise's familiar. Unhappy with the arrogance of nobles, Saito exposes Guiche's two-timing nature as an act of revenge. This of course, provokes Guiche into challenging him to a a duel. Despite being severely beaten up by Guiche's magic, Saito refuses to bow down. Impressed, Guiche tosses him a sword to even up the playing field. In a completely unexpected turn of events, the runes etched on Saito's hands begin to glow the moment he grasps the sword. Feeling a surge of energy, Saito manages to defeat Guiche. However, he soon collapses after the fight from fatigue.

With his recent victory over Guiche, Saito has become semi-popular among the commoners and several nobles. Kirche in particular has chosen him as her next boyfriend. In a devious plan, she attempts to seduce him, although this fails when Louise finds out. Annoyed by Saito's lack of defenses, Louise drags him out to town to pick up a sword after considering his hidden talents. Kirche, unwilling to let go so easily, matches Louise's gift with a more impressive sword. Of course, it simply causes more problems between Saito and Louise.

Louise tries to prevent Saito from looking at other girls, but her plan fails. The newly crowned Queen Henrietta assigns the code name 'Zero' to Louise for a mission. When they get home Louise insists she tell him about the misunderstanding that Agnes said. When he tried to explain she beat him until morning causing bruises all over his body. The next morning, Saito and Louise are informed that Henrietta has been kidnapped.

The supposedly dead Wales appears and takes Henrietta to Albion. He uses his vow from their earlier days to convince her into following him. Saito and Louise goes to rescue Henrietta. Wales, later revealed to be revived and controlled by Cromwell's ring, is defeated by Louise with a dispel spell. Wales is released from the control of the ring and asks Henrietta to make a new vow with him before dying again.

Julio Cesare transfers to Louise's school and shows an interest in her. He challenges Saito to a fight in which the winner gets to kiss Louise. Saito receives special training from Agnès but Louise shows up and attacks Saito in a jealous rage yet again. He fights against Julio the next day, but Julio loses on purpose.

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. He reassures he will not leave despite the absence of any contract. However, when he tries to have sex with her, she blows him up.

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. Louise tries to protect both of them against Sheffield, but her void magic isn't strong enough. Out of desperation, Louise tries to summon Saito as her familiar again even though it seems impossible. To her surprise, Saito appears and Sheffield was thrown off guard. Due to this, Sheffield retreats and Saito and Louise renew the contract with a kiss. Saito gets the "Gandalfr" runes burned into his hand again.

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.

Queen Henrietta has ordered everyone to Romalia, once there they meet the Pope of Romalia, Saint Aegis the 32nd. He has summoned them to reveal a secret, one that involves void mages and the fate of the world.

King Joseph has developed a weapon of mass destruction and needs the help of a void mage. With three mages to choose from, which one will become his unfortunate pawn?

King Joseph new weapon is a bomb fueled with Louise’s Explosion spell. Will Saito, with the aid of a new “out of place relic,” reach Louise in time before she makes the ultimate sacrifice?