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.

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.

Baggage City Arc

 * Main article: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.

Ichihanaran Festival Arc

 * Main article:Ichihanaran Festival Arc

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 Teitoku 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 suppose to take. Although, she seems quite fine and even intrigued by the events that unfold.

Teitoku first contacts her after he finds Fräulein Kreutune. Teitoku tells her that he wants to the mission his own way, to which she agrees, saying that Teitoku 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 Teitoku's White Beetles' differing interpretations of Teitoku'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 Teitoku. 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 Teitoku, 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 turn 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 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 overthinking 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 recorde 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 sombody 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.

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.”