Kihara Enshuu is a character introduced in Shinyaku Toaru Majutsu no Index as a member of the infamous Kihara clan.
Despite being referred as someone who is not qualifed as a Kihara, she is perhaps the most surprising member of its family introduced during the attack of Academy City on Baggage City. She is arguably the most active and most dangerous Kihara during the attack.
She is constantly trying to prove herself as a Kihara. Enshuu lacks a certain "Kihara-ness" even as a member of that family, stemming from her isolated imprisonment as a child. Even though she cannot perform the multiplication table, write even katakana, much less kanj she is not stupid, but simply was not taught those things. Even without this fundamental knowledge here mind naturally comprehended science from everything around her. Even for a Kihara without having anyone teach her the border between good and evil, she naturally gravitated for the most evil and pure form of it.
Enshuu displays a timid and naive demeanor, that befits her image of a little girl. Her naivete is carried when she is doing things that might harm and killing people, as if she does not understand the true context of her actions. She is described by the author as something like a robot, as he initially wanted her to a robot. This may explain her nature, and why she needs to borrow the thought patterns of other people, most especially the other Kiharas to do actions that would create a satisfactory result for her.