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

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.