Kihara Yuiitsu

Kihara Yuiitsu (木原唯一) is a character introduced in Shiyaku Toaru Majutsu no Index. She is a member of the Kihara family who appears at the end of Academy City's attack on Baggage City. She appears frequently behind the scenes, manipulating people and events in the background. She later becomes a recurring antagonist after Kihara Noukan is severely incapacitated by Kamisato Kakeru, and later swears revenge on Kakeru and Aleister Crowley. Her quest of revenge torments not only Kakeru and Kamijou Touma but all of Academy City.

Etymology
As part of an apparent trend to the Kihara family having names related to science or mathematics, Kihara Yuiitsu's given name (唯一) can be translated as "Single", "Sole", "Only", and "Unique".

Appearance
Yuiitsu is a young woman of an unspecified age who wears a ready-made cheap suit, making her look like she's going to a job interview.

Personality
Like all Kiharas, she has the tendency to do actions in the most evil way possible and has the natural aptitude towards science and experimentation. She uses people for her own needs in experiments, as what she did to Yakumi Hisako of the Academy City Board of Directors, who apparently became the hapless recipient of her intellectual curiosity. She apparently has the tendency to lose motivation in things if she is unable to find something of interest in it, and most likely easily overlook things that can be seen if properly analyzed, as with her conversation with Kihara Noukan seems to imply.

She greatly admires Kihara Noukan, even calling him "sensei" and reverentially bowing to see him off, though sometimes treating him like an actual pet dog. Later, Yuiitsu showcased genuine care and worry for her teacher, and was driven to tears on seeing Noukan mortally injured and after placing him into cold sleep, sought vengeance on everyone and everything which had brought him to that state. She also started to mimic some of her teacher's traits, such as his tendency for, and describing things between like and dislike, and good and bad. However, she has also deliberately taken actions differently from what he would have done, seriously following her teacher's last words to her to surpass him and aiming to become "unique".

Background
Due to the fact that Freshmen was set up to specifically input the values required to make Fremea Seivelun the bearer of Agitate Halation, Yuiitsu apparently had implanted her intellectual curiosity into Yakumi Hisako without her knowing in the same vein as the Dark May Project, combined with Hisako's field of expertise led to the Agitate Halation Project. Apparently, it was for the simple fact to make her a subject of her experiments. She later met Hisako personally herself, and due to inserting her personality into her, got along well.

She apparently has enough political power and know-how to be the one to negotiate with the Baggage City leadership, and under favorable conditions to Academy City. She also held a number of positions, including that of Academy City's Hypothetical Disaster Planning Calculations Director. At one point, she wrote a crisis management manual for a hypothetical destruction scenario involving a complete city-wide blackout.

Baggage City Arc
Yuiitsu is sent by Academy City to Baggage City with very sensitive, top-secret documents and to negotiate with the now decimated Anti-Academy City Science Guardians. She speaks with an old man who sets the Guardians' policies and forces his hand by demonstrating that it would be best to end the conflict now, while negotiating she uses that argument that if Academy City were to weaken and no longer be the capital of the Science side, the Kihara Family would spread throughout the world, a fact that terrorizes the old man. He agrees to sign the papers Yuiitsu brought with her, which ends Baggage City's involvement in the conflict against Academy City.

Eve of the Festival
Yuiitsu goes to a secret underground laboratory beneath School District 3, where Kakine Teitoku is apparently still alive and is sealed in a giant room covered in a silkworm cocoon-like substance. There, she explains to Kakine the situation with Fräulein Kreutune and asks for his help with the situation. She understood that Kakine would likely cause chaos and destruction, but since she is a Kihara, it doesn't matter to her. Thus, Yuiitsu lets him loose in Academy City, interested in her research between the difference of the two top ranked Level 5s, Accelerator who ruled over destruction, and Kakine who ruled over production. A comparison she finds somewhat intriguing because she felt like she could see some truth about the essence of science in that fact.

Day of the Festival
For the most of the arc Yuiitsu monitors in the mission Kakine Teitoku was supposed to take. Although, she seems quite fine and even intrigued by the events that unfold.

Kakine first contacts her after he finds Fräulein Kreutune. Kakine tells her that he wants to the mission his own way, to which she agrees, saying that Kakine should smash the worst case hypothesis the Kiharas have come up with. She concludes that the destruction he is going to cause will sure to have a wonderful meaning to science.

It is unknown on how much activities she could monitor. Nevertheless, she was several things that have occurred during the arc. She was aware of Kakine's White Beetles' differing interpretations of Kakine's oral command. She comments on how it is like a form of narrowing down ideas, and while saying that it is not good, an expression of pure enjoyment falls upon her face.

At the end of the events, Yuiitsu hung out inside the facility that held Kakine. Alone, she takes a voice recorder to comment on the things that have happened. She states that the Dark Matter has cleanly disappeared, and have requested examinations to take samples on the surface of 40 different locations, though doubts if anything will come out of it. She then pulls out a devices that can connect to the City's SNSs and message boards. She comments how there urban legends regarding Kakine, and that someone from the dark side of Academy City is spreading those rumors. She then tags it yellow. She then comments on Accelerator's development, stating that even though malice was injected within him, it is not clear if it will bloom into anything, stating that it would be a waste if he remained as he is. She adds that it would be nice if he could become something more grotesque with his wings.

She comments on Takitsubo Rikou's progress, referring to it as going "exceeding well," tagging her interest with her as gold. On Fremea Seivelun, she comments on how that her esper power, Agitate Halation, is confirmed to have been used unintentionally. She tags her interest with her as platinum, remarking on how one must be extremely careful when gathering data.

She then turns off her voice recorder, but switched it back on after gathering her thoughts. She comments that with Fräulein Kreutune, it is out of her jurisdiction. She states that she is rather unhappy with it, but from what she has observed, she has a durable body that can't be killed no matter what, a heart that desires friends, and the possibility of being controlled regardless of her personal beliefs. This leads her to conclude that she is very similar to Kazakiri Hyouka, and references that it connects a single thread from Fräulein, Hyouka, and Aiwass. She states that she may be over thinking in including Aleister Crowley into this connection as well, supposing that she can draw the line between the chairman and Aiwass.

Finally, after switching on and off her recorder a few times, Yuiitsu finally comments on the intruders in Academy City, the magicians. She states that there are similarities that have been identified that are similar to the ones that was witnessed in World War III and Baggage City, but says that it too is also outside of her jurisdiction, and says she will leave it to somebody else. Her words trail and becomes silent. She then sighs and lets go of her voice regarding falling to the floor and getting crushed by her foot. She then strangely lets out a voice that says that what she is doing isn't Kihara-like at all, a phrase that was once often used by Kihara Enshuu.

Agitate Halation Arc
It is implied that she is the Kihara who Rensa references to have given the report regarding Fremea's progress, likely about the Agitate Halation.

For the most part of the events of the "heroes" rioting in Academy City, Yuiitsu acts as an observant, though predicting that the experiment will fail. After the Agitate Halation Project's failure, Kihara Yuiitsu and Kihara Noukan apparently influenced the "heroes" to stop rioting after the defeat of Rensa and Yakumi Hisako. She is seen with Kihara Noukan walking in a park in School District 13 the morning after the incident. She commends Hisako for being a nice patron to her despite the failure of the project, to which Noukan replies that she may have been playing around too much. Noukan mentions on how Yuiitsu managed to implant her intellectual curiosity with Hisako but not being able to make Hisako to understand how a Kihara thinks. Yuiitsu laughs, recalling on how Hisako wondered on how they got along so well, and commended her for being useful to her research. Noukan however states that she went too far, but Yuiitsu says that she has learned her lesson.

Noukan then tells Yuiitsu of the top 3 likely candidates to become board of directors as insurance for her plans. But Yuiitsu simply vetoes it, saying that it isn't Kihara-like, prompting Noukan to ask of her plans. Yuiitsu then mentions the use of the Shadow Ruler plan, apparently an organization, to which Noukan throws doubts at such a convenience that she can use. Yuiitsu states that they will take action if they make them think there is a reason to take action, pointing out Academy City, the city of science, and its strange relationship with jinxes and urban legends. She says that she can manipulate a bit of information to make certain facts seem true, which will prompt them to action in lines with her schemes, mentioning the M-Fund and the UFO Investigation Committee as examples. She then asks Noukan to start deceiving important people. Hearing this, Noukan acquiesces to her plans, stating that he can give two or three people she could use in her plan, rich social climbers that are dumb enough to be manipulated by her. Hearing this Yuiitsu thanks to him as always.

With the Agitate Halation dead, Yuiitsu then asks what they should do about it. Noukan states he has no particular interest in but tells her that it might not be a failure. Noukan states that the Level 5s of Academy City gathered in one place despite Hisako's wishes, as well as Kamijou Touma's appearance of his own free will despite the Imagine Breaker negating any influence from Agitate Halation. He tells Yuiitsu that even though the experiment ended in failure, perhaps Agitate Halation was simply too much for her to handle, and that there may still be something of interest. Yuiitsu agrees with his analysis, to which Noukan states that she never shows any motivation if he is not the one keeping score for her.

Magic God Othinus Arc
For reasons unknown, Kihara Yuiitsu insists to Amano Kaguya to use the S5 cannon on the Hikoboshi II to deliver Accelerator, the cargo of said cannon, to Denmark, where he is supposed to kill Kamijou Touma and Othinus. Kaguya says to Kumokawa Seria who had come to visit her that she supposes that she should keep it a secret from Accelerator.

Mental Out Arc
She is first seen with Kihara Noukan in a pet cafe, trying to eat a puppy cake, much to Noukan's chagrin. Having enough of Yuiitsu's teasing, Noukan demands her to get to the point. Yuiitsu tells Noukan that Shokuhou Misaki has noticed the manipulations done by Mitsuari Ayu. Moreover, Yuiitsu tells Noukan that Ayu has begun moving as well, taking over her entire section from within for her use after Misaki noticed. Their conversation later devolves into referring Mitsuari as an "ant" in reference to her name in kanji having of ant in it, and comparing her to the samurai ant. Yuiitsu then laughs as the prospect of Noukan's "work" becoming more violent. Noukan then says that he isn't fond of Yuiitsu's tendency for destruction and says that he dislikes unnecessary destruction, adding that what he is saying is more about his likes and dislikes instead of good and evil. Yuiitsu replies that he doesn't really get him and then pouts. She tells Noukan that what he said means that he is willing to sacrifice millions of people as long as it is necessary, and asks how it is any different from her or any Kihara. Noukan says that it is an issue of likes and dislikes, and scenarios like the one she presented cannot be helped. Noukan says that because of that there will always be a place for horrible individuals like himself.

After the defeat of Mitsuari Ayu, Noukan is out for a walk in School District 15 with Yuiitsu. They later come upon the Celestaquarium for Noukan's 72nd and final request from Aleister Crowley, the elimination of Shundou Toshizou. Yuiitsu says good luck to Noukan, to which the latter says to wait somewhere away from there as he thinks it is going to be rough. Despite his warnings, Yuiitsu returns near the facility and presumably witnesses the destruction that Noukan caused. Already four in the morning, Noukan meets up with Yuiitsu again, who states that she came back because she couldn't help herself. Yuiitsu suggests in getting a quick meal, to which he declines, much to her disappointment. Noukan then sends communication request to the Windowless Building, prompting Yuiitsu to say that he doesn't have to suck to Aleister Crowley. Noukan states that the Kiharas cannot defeat Aleister Crowley, to which Yuiitsu understands that it is because of his Archetype Controller. Here, Noukan notes that with that power he will able to cut the Kiharas off from their surroundings making science into the archetype of being heretical, making the very definition of their existence non-existent. Yuiitsu remains silent during Noukan's conversation with Aleister.

Magic God Invasion Arc
As the High Priest is bringing the Arrowhead Comet towards an impact on Academy City, Yuiitsu has a brief conversation with Noukan before he leaves to deal with the Magic God, discussing the information they had scattered to manipulate the flow of people during the situation (including some regarding the liquid diamond) and Noukan's idea of romance, making a comment on the use of a giant drill seeming like phallic compensation to an amateur like her, which causes Noukan a little embarrassment.

World Rejecter Arc
The night after Noukan killed the High Priest and stopped the Arrowhead Comet, Yuiitsu cooked him dinner in her luxury apartment. She sat down to eat her dinner with him but had only just started on her salad when he had finished his. After being complimented on her cooking, Yuiitsu mentioned how he was having maintenance done to his weapon and how he had said it wasn't over yet, with Noukan mentioning how he was bothered by how the Magic Gods had suddenly vanished, considering it fishy.

Later that night, Yuiitsu found Noukan, severely beaten after his clash with Kamisato Kakeru and close to death. Breaking down in tears on seeing Noukan's mortal injuries, Yuiitsu tried to figure out a way to save her teacher. Unable to save him with the time and technology available to her, Yuiitsu took Noukan to a nearby facility, deciding to place him into cold sleep in the hope that he could somehow be saved in the future. As Yuiitsu prepared to put him in cold sleep, Noukan used his last chance to speak to her to encourage her to grow and surpass him, adding he had nothing more to teach her. Immediately afterwards, he lost consciousness as Yuiitsu activated the flash-freezing process. Having succeeded in preserving her teacher, Yuiitsu vowed that she would surpass him, go beyond 'Kihara' and become something truly 'unique', adding it would be the romantic thing to do.

Element Arc
After the Kamisato Faction disappeared, Yuiitsu devised and unleashed the Elements on the city in order to draw them out of hiding. After encountering the Elements and discovering their reduced activity in temperatures over 42 degrees Celsius, Fran used her space station to flood the city in microwaves and create an intense heat wave exceeding 55 degrees in order to slow them down. During the heat wave, while the Elements were loose in the city, Yuiitsu lay in wait below the Windowless Building, using a system comprised of Class 0 Elements and a network of ultrasonic wave receiving stations to monitor the blacked-out city.

As part of her plan to draw out her enemies, Yuiitsu positioned a lure in the form of the Crystal Tower. On December 8th, when an expedition from Tokiwadai Middle School, including Misaka Mikoto and Kamijou Touma, destroyed the tower, Yuiitsu led the Elements in an attack on School Garden, overwhelming the defenders and severely damaging Tokiwadai, with particular focus on the hangar housing Mikoto's Anti-Art Attachment. She then ambushed the expedition on their way back but broke off the attack after several members of the Kamisato Faction interfered.

When the Kamisato Faction, together with Touma, finally confronted her beneath the Windowless Building on the morning of December 9th, Yuiitsu devoured the remaining Elements to create her own version of the Anti-Art Attachment. She fought the group with the unit and held her own, but they eventually overcame her. However her final gambit with the building's rocket boosters forced Kamisato to use World Rejecter while holding conflicting desires, in order to save the others, which resulted in him being exiled as well. Yuiitsu then reclaimed his right hand, and used the possibility of saving him with the hand as well as the threat of it being lost, to force the Kamisato Faction to attempt to kill Touma.

Abilities
As with other Kiharas, Yuiitsu possesses considerable scientific knowledge and intellect. Her researcher's mind is capable of taking into account conditions, tools and possible methods, and calculating the values and steps in order to reach a goal, even when Yuiitsu herself is under immense distress. She also possesses a degree of forensic and investigative capabilities. She is capable of making careful plans for hypothetical scenarios, such as required in the position of Academy City's Hypothetical Disaster Planning Calculations Director.

Yuiitsu has created a number of tools which she uses, such as the UL Exploder (横紙破り), an oddly-shaped gun resembling a starting pistol for a race, which gathers and detonates the UNDER_LINE nanodevices in a false dust explosion and for a very short time creates a space which can't be monitored. As such, the UL Exploder only works inside Academy City. She also uses a device resembling a stun gun that was originally used amplification circuits to send out a high power pulse to destroy electronic circuits and unlock doors, which she has further modified to destroy the electric signals stored in cerebral nerves and erase the short-term memories of anyone within ten meters.

She also makes use of an imitation of one of Kihara Amata's techniques, which uses shockwaves propagating from multiple points of impact, having them collide within the body and create deadly bubbles inside the blood vessels, regardless of whether an opponent blocks her attacks or not. She also makes use of her lab coat in order to divert the paths of attacks slightly to avoid direct hits.

Using a combination of Sample Shoggoth and an attenuated St. Germain virus (弱毒性サンジェルマンウィルス) she'd cultivated from a sample in her mobile laboratory, Yuiitsu was able to sew Kamisato Kakeru's severed hand onto her arm and rewrite her brain to trick its recognition so she would be recognized as the owner of the hand, allowing her to use World Rejecter, though she required the trigger phrase in order to do so. The combination also allowed her to produce imitations of the Magic Gods and their attacks as part of a bluff that she had the real ones at her disposal - Sample Shoggoth's shapeshifting abilities allowing her to produce fake models with their forms and the attenuated St. Germain virus allowing her to use magic, specifically relating to carbon and plants, and prepared in forms to aid the deception.
 * Pomegranate seeds (ザクロの粒): One of the spells used by Yuiitsu as part of her deception involved pomegranate seeds, based on the legend of Persephone/Proserpina who was taken to the underworld and tricked into eating a pomegranate from there, binding her to the underworld and death. The seeds are fired as high-speed projectiles and leave masses of darkness the size of baseballs, which appear to bend the light from their surroundings, sucking it into towards the center.
 * Elements: Using a combination of her magical and scientific knowledge, Yuiitsu created these artificial, reduced life forms, which she unleashed on Academy City to draw out the Kamisato Faction. A hybrid of science and magic, the bodies are created in the shape of animals and plants, a reverse of the process which converts the remains of animals and plants into petroleum over long periods of time. As this method can create an outward form but can't give it a soul or life, a magic-based core is used to animate the body. The Elements are capable of using to blend in with their surroundings, and can use elemental attacks corresponding to their core.

Anti-Art Attachment
During her battle with the Kamisato Faction below the Windowless Building, Yuiitsu constructed her own Anti-Art Attachment, devouring the remaining Elements to use as material for the unit. Yuiitsu used a different approach from Noukan, without any help from Aleister, and as such her Anti-Art Attachment isn't connected to Aleister and his power. As Yuiitsu doesn't fully understand the original, she is only reproducing its destructive power. Being constructed from Elements, Yuiitsu's A.A.A. shares some of their traits, such as their ability to blend in with the background and their vulnerability to Imagine Breaker.

Yuiitsu's A.A.A. has a cold yet streamlined and biological appearance, with large portions being translucent. Sharp, crystalline protrusions extending from her back, form a pair of giant wings, with other protrusions resembling eyeballs, claws and fangs. Two long, narrow boosters are positioned on the back of the unit and produce a red light when lit. The unit includes a variety of cannons, lasers, anti-air guns, launchers and armor parts. One of its notable weapons is a giant anti-special steel chainsaw, with 'Dog's life' and a golden retriever head logo inscribed on its surface. The unit also has a variety of sensors and other features to assist in aiming and diverting impacts.

Character Art Design
According to Haimura Kiyotaka, Yuiitsu's concept was to be normal looking, unlike the girls from the Kamisato Faction.

Quotes

 * (From NT6): "Ahh, ahh. This just isn’t Kihara-like at all..."
 * (From NT7 referring to Yakumi Hisako): "She had been wondering why she got along so well with me. She had my thoughts implanted into her, so of course we got along. She was excellent as a patron who let me do anything I wanted. It was like she was my knight in shining armor. I had all the funding I wanted and all the authority I wanted."
 * (To Noukan, from NT11): "Nooo, you’re a dandy gentleman!! I can’t get enough of that voice!!"