Kanae Kuroshiba (黒芝 かなえ Kuroshiba Kanae) is a student of class 2F who is often seen with a book in Hollow Mirror Field and she is later revealed to be the true mastermind behind the doppelganger incident.
Kanae is first spoken of by Kaori as a very beautiful girl. She has red eyes and thigh-lengthed black hair.
She is always seen in her uniform, which is a little longer than the school's standard. She also wears a red Dutch hat and a black ornament on her waist. Her only different appearance is the dark blue outfit she wears in the finale of the story. Compare to her discreet school uniform, this second magus outfit of hers is much more revealing; her hat also changes from red to blue with yellow outlines to match with her costume. In her uniform, she wears black tights and black boots, which changes into high-heeled shoes when she dons her battle dress.
Kanae is overall knowledgeable and very intelligent, to the point that it makes her manipulative. She usually speaks with a polite yet teasing tone and her words, to an extent, are somewhat cryptic. However, she seems to hate it when her plans go astray. When this happen, her tone would change from teasing to threatening. She is also shown to have some affection towards Shuu; during the final battle, she even attempted to seduce him with her sex appeal. This, however, is mostly due to the fact that Shuu is the successor of modern magic, which can help her create a new race of magi in the future.
Kanae's true name is Kanae Kuroshida (黒羊歯 鼎 Kuroshida Kanae). She came from the Kuroshida clan, a clan of Japanese that researched western magic. The clan was massacred by Index before World War II. Kanae herself doesn't seem to care about revenge, as she claimed it is boring. She is also a member of the Magic Association of Thule, a magical organization created by the Nazis during World War II, which consisted of seven extremely powerful dark art users to oppose and try to eliminate Index. She seemed to have been staying in Japan even before 1945, although it is unclear whether she came before or after Lieselotte did. Around 2009, she cast a spell on the students in Kouryoukan Academy and made them think she was a student called Kanae Kuroshiba. Adopting the title of The Witch of the Library (図書室の魔女 Toshoshitsu no Majo), she is known as an intelligent yet aloof beauty who spends most of her time in the library.
Lying in Wait
The Library's Witch
On September 17, Shuu led Kaori and Tadashi to the library to meet Kanae; they asked her about the Doppelganger. Kanae gave them a detailed definition of a doppelganger and told them what she thought about the missing cases. However, she kept secret about its true objective and the truth that she was the mastermind behind the incident.
Return to Origin
On September 24, Kanae returned to Weweslburg Castle to revisit the place where Thule's headquarters used to stand. She reviewed Thule's situation a final time. After World War II, Thule was disbanded. Sophia Measley was roaming free for her mad scientist fetish. Fu Manchu was currently a mafia boss in Asia, working on a slave market. Walter Dietrich was killed and Lieselotte Werckmeister had gone missing, both in Japan. Only three people, including her was still secretly going for world domination. Kanae contemplated on her plan: going to Japan and starting domination there, and, at the same time, checking on Lieselotte. If Lieselotte was alive, Kanae would offer the position of ruler to her. Having her plan set, Kanae left the castle and returned to Japan.
A Day Off
On September 26, Kanae went to the park to meet up with Shuu. When Shuu arrived, he saw her holding a black cat in her arms. The cat rested comfortably in Kanae's arms, but when Shuu tried to scratch its ear, the cat rejected him. Kanae joked that he might not like Shuu's body odor, much to Shuu's dismay. She then asked him what he would like to do, which Shuu was unable to think of anything. Kanae expressed her disappointment, although she might have only said that to mess with Shuu's head. She decided to sit down and read, which embarrassed Shuu yet again when she took off her stockings. Shuu was mesmerized seeing Kanae's reading in the sunlight, which he thought was like an artistic sculpture. Kanae told him not to look at her too much even if she was beautiful, which made Shuu flustered.
Later on, Shiori came to the park a few meters away from the two. Kanae told him [that girl] was a genius, saying that she remembered everything in the library after reading them only once. She said that she felt a little jealous and that she might have to give the silver-haired girl the title Library's Witch. Shuu asked where that name came from. Kanae revealed that the name originally belonged to Mutsuko Hirohara, an ex-student at the academy and also the best, scoring top in every single subjects. She said that Mutsuko was called a witch because of her devotion to books and it was her who revolutionized the academy's library, making it almost like a city level library.
Battle of the Mirror Field
The Witch's Challenge
On October 19, when Shuu and Shiori came to the library as usual, Kanae told them to stay and have a cup of tea as she had something very interesting that she wanted to discuss with them about. At first, she asked them if they knew the meaning of the word "Episteme". Both Shuu and Shiori answered her question, showing their knowledge on the matter. Kanae then told Shiori that she has such a simple view of things, despite being an apostle of Index, which surprised the both Shiori and Shuu. As they were bewildered, Kanae activated her Specialized Bounded Field and restricted their movement at the same time. She said that she could kill both of them at the moment, but that wasn't her intention because she had something to offer them.
She revealed her plan of using the Artificial Emerald Tablet to disable the use of magic around the world, making her and the remaining members of Thule the ruling force. However, Thule at the time was in an unstable stage; three out of seven had already stopped working for the organization and even Thule's leader, Lieselotte Werckmeister, was no longer interested in leading Thule and attempting to destroy the world. Therefore, she offered them, Shuu the direct successor of modern magic and Shiori, or rather, Ursula the ultimate weapon of Index, two vacant seats in Thule. She told the two that they should think over the matter carefully, but threatened that she would not take "no" for an answer before leaving. As she walked out of the library, her Specialized Bounded Field was deactivated and Kanae herself disappeared to somewhere.
On October 22, Kanae waited for Shuu and his friends in the park. She asked about their answer, only to be rejected. Disappointed in the gang, she activated her Specialized Bounded Field and told them to come at her, starting the battle.
Shiori took the initiative and started the assault by pouring a rain of magical energy on Kanae. The spell did not work and Kanae retaliated with her magic. Shuu and Mio managed to put up Winter Orbit as a shield, which timely prevented them from being hit by two shots of lightning. Kanae began her counter-attack, beginning with disabling the Doppelganger's core, which was enabling Shiori to move inside the mirror field. Having no choice but to fight without Shiori, Shuu and Mio used Baldanders to strengthen their magic power and began their own assault. Mio shot electrical arrows of Tesla Javelin at Kanae while Shuu used Ice Cube, attempting to confuse her, but their combination also could not do anything on her powerful defense.
As the spells hit Kanae's magic formation, Shuu lost sight of her. He tried to look around to find her, but Kanae quickly closed in and froze his entire body. She said that it wasn't too late to take up her offer (this time she even went so far as to use her sex appeal to seduce him), but Shuu strongly rejected her again, making her angry. Since no attacks worked on Kanae, Mio requested a one-on-one duel with her to buy time for Shuu. Kanae accepted her challenge and create numerous magic formations to attack her. As the battle prolonged, she grew suspicious of Shuu's intention, as his actions indicated that he was waiting for something. She then used Exhaustive Search, a modern spell to scan Mio and picked the two spells Demanufacturer and Nuker to torture Mio, thinking that it would bring Shuu into action. The spell she chose destroyed Mio's internal organs, but Mio refused to give in and was able to stay awake until Exhaustive Search was completed.
After the process of Exhaustive Search in Shuu's phone was completed, Kanae stopped assaulting Mio and attacked Shuu. To her surprise, he copied her spell and countered her attack, bringing the battle to a temporary tie. Shuu then weighed her down with a gravity spell but surprisingly, she was still able to counter him with modern magic the way he did her. As Shuu was being incapacitated, Shiori finally came to herself and dealt a final blow, seriously injuring Kanae. Kanae did not die, however. She told them that with her defeated, there would be no one else to stop Lieselotte from destroying the world. A magical circle then started to appear under her while she told the gang that Golvas is summoning her back. As Shuu was going to stop her from escaping, Shiori warned him to stop, saying that stopping such a summoning spell will cost him his life. She then slowly disappeared, laughing hysterically in the process.
- Artificial Emerald Tablet (人工翠玉碑 Jinkou Suigyokuhi): While being powerful herself, Kanae still possesses a specific device that can further support her, which is the Artificial Emerald Tablet. With it, she can expand a very powerful Specialized Bounded Field. She is considered to be the strongest individual that wields too much power which can destroy the entire world.
- Mirror Maze (鏡界 (ミラル.メーズ) Miraru Meezu; lit. "Mirror Barrier" in Japanese): Kanae's Specialized Bounded Field, which is a green reversed world that does not have any special abilities except to only take in the people she wants, and is closely connected to the Artificial Emerald Tablet. The device is a tool that helps ensure her victory against any kind of enemy. While under construction, the Artificial Emerald Tablet allows her to tune magical power within her mirror Specialized Bounded Field to her own advantage so other people can't activate their sorcery inside it. Since the Artificial Emerald Tablet needed the sacrificed life forces of people with certain genetic trait and would be completed once the ten thousandth victim is sacrificed, she sent the Doppelganger to kidnap and sacrifice the victims' life force to it inside her mirror Specialized Bounded Field. Upon completion, the effect of the tablet would extend to the whole world and she would basically be able to dominate the world since there would be no magi or other sorcery users to stop her.
- Extended Lifespan: Despite having a young appearance of a high school girl, Kanae's age is in fact unknown. She claims to have been born even before World War I, suggesting that she is well over a hundred years old.
- Unlimited Magic Power: Kanae is an extremely powerful witch. She is even more powerful than Shiori and is able to call for her Specialized Bounded Field, by just a snap of her fingers. In fact, she can cast most spells without chanting any incantation at all. Despite the fact that her Specialized Bounded Field prevented Shiori from using all of her power in the final battle, Kanae repelled the combined efforts of Shuu and Mio without any difficulties at all. When she took Shiori's Pallida Mors, which is akin to a nuclear explosion, head-on, her immense magical pressure enabled her to survive the powerful attack.
- Enhanced Physical Capabilities: Kanae's magical power stock seems to act as a passive enhancement for her physical body, which is no different from a normal human girl. She has shown to have quite some strength, lifting Shiori with one hand while choking her.
- Magical Power Masking: Despite having a tremendous amount of power, which Kaori commented that it was like cheating, Kanae can effectively mask her own magic signature for covert movements even on an all-out battlefield. She uses this ability to both minimize damage and confuse her enemy.
- Teleportation: Kanae seems to dislike physical labor, thus she only uses teleportation to move around the battlefield. This ability allows her to have more options in timing for approaching or retreating more efficiently.
- Immobilization Magic: Kanae can easily catcht her opponents off-guard by somehow interfering with the inner activities within the body. Once the prey is caught, she can easily claim her victory. However, this ability seems to have some strict requirements and cannot be used without the element of surprise as she did not use it during the final battle.
- Advanced Defensive Barrier: Kanae possesses some kind of barrier which can perfectly defend her from all kinds of attack. The magic circle for the barrier is larger than her own body. It was used to defend her from Shiori's Nameless Kaltz
- Lightning Strike: Kanae's preferred method of offense is releasing a single black-purple lightning strike at each of her opponents. While it is her basic attack, the power is so tremendous that Mio's and Shuu's Winter Orbit were shattered right upon contact.
- Lightning Barrage: Kanae can set up multiple magic circles on the sky and let them release Sylph-based beams on her enemies. While this attack does not reduce Kanae's magical power much, the sheer number of attacks makes it devastating enough to wipe out an entire army. It is also useful in pinning down the enemy to prevent them from escaping, although there are few who can survive such a barrage, provided by Kanae's massive magic capacity.
- Azi Dahaka (アジ＝ダハーカ Aji Dahaaka): As Kanae chants an incantation, the Artificial Emerald Tablet glows and a massive black magic circle appears in front of her. Sylph-Larva energy then gathers at the hole at the center of the circle to be compressed to the bare minimum. After the maximum amount of energy is charged, the compressed magical power is forcefully released from the hole of the magic circle as a cohesive beam of energy. This is Kanae's most powerful attack and one of the few spells that a full incantation is required. This spell also allows Kanae to bring destructive force that can annihilate the entire world.
- High Intellect: Aside from having tremendous magical powers, Kanae appears to be the intellectual type. She is knowledgeable about almost everything, especially magic, and is probably the only magus of the old generation who possesses knowledge of modern magic. In the final battle, she used modern magic to assault Mio and was even able to use Gravity Fall to stop Shuu's movement while being affected by Shuu's Gravity Fall herself. Also, she seems to be well aware of the Red Night and its purpose, but she avoids letting others besides Shiori know that fact.
Shuu Amami: Shuu and Kanae got along well until the truth about her identity is revealed, helping him when he needed in the library and interacting with him a lot. She seduced Shuu in battle just because he was a Modern Mage
Lieselotte Werckmeister: The two of them were in Thule, with Lieselotte as her leader. Kanae seemed to really admire her, but their plans were different, and Kanae did not want her to destroy the world.
Shiori Momono: Kanae introduced the job of librarian to her, and the two didn't really have a bad relationship at the beginning, despite Kanae being a bit jealous of her, as she did her job better than her, and called her "Ninjyo" which meant "doll" for mocking her. Later, she became her enemy, but lost in the final battle.
- Kanae's surname Kuroshiba means "black" (黒) (kuro) and "turf, lawn" (芝) (shiba).
- Kanae has a Kirakishou-Suigintou complex with Lieselotte.
- Kanae mainly uses lightning-based attacks.
- The title Library's Witch is originally not hers, it belonged to Mutsuko Hirohara (Yukiko Hirohara's aunt), who was Saiko Akamine's rival and who, according to Yukiko, as the story happens, is working as an investigator with her admired Tsukiko Hirohara (Yukiko's older cousin) in Tokyo.
- According to Kanae, it was Mutsuko who revolutionized the academy's library by adding a considerable amount of books, manga, light novels, etc. Kanae took the title to show admiration for Mutsuko.
- Her Thule's name: Zorn, was, in fact, not mentioned in the whole series, even by Kanae herself, but was only written in the part about Thule on the official main page of 11eyes: Resona Forma.
- Kanae's strongest attack, Azi Dahaka, is a reference to Aži Dahāka, an evil figure in Iranian mythology and also the most significant and long-lasting of the ažis of the Avesta, the earliest religious texts of Zoroastrianism. He is described as a monster with three mouths, six eyes, and three heads (presumably meaning three heads with one mouth and two eyes each), cunning, strong and demonic. But in other respects, Aži Dahāka has human qualities and is never a mere animal.