Kihara Yuiitsu

Kihara Yuiitsu 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. 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. 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 romance, 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".