Yotsuba

Yotsuba (四葉) is a minor character of the Science side and is a female member of Judgment who wields a telepathic ability of level 4 and debuted in the Kazakiri Hyouka Arc.

Kazakiri Hyouka Arc

 * Main article: Kazakiri Hyouka Arc

She disclosed that in emergency situations member of Judgment are requested by Anti-Skill to assist in emergency operations by coordinating the silent evacuation instructions to the civilian inside the underground mall in order to isolate the terrorist and begin suppressing operations, she also carried a picture of the terrorist on her cellphone as to instruct "evade this person" to the people that inquired further in the situation. Unfortunately for her, before she was done with evacuating the civilians Sherry Cromwell, the terrorist; attacked and caused the entrapment of everybody inside the underground mall. It is presumed that as soon as the terrorist attacked Yotsuba was busy keeping the calm civilians and instructing the proper emergency exit measures, the same thing that Shirai Kuroko did on that situation.

Abilities
Her esper power is a telepathic class ability which she simply reffered as "Telepath". She can speak directly into people minds without giving any obvious sign and with no need of engaging in physical contact. The novel described that her ability works like an invisible tube or cord that establishes between herself and her target through which she can send and receive messages, through this method she refers to her thoughts as 『Voice』 (『声』). , it was also stated that Yotsuba can "regulate" the volume of her voice; show as when she did her second try at reaching Kamijou Touma's mind.

Quotes

 * (To Touma) "Can't you hear my 『voice』? Look!"

Trivia

 * Yotsuba biggest contribution to the To aru universe was certainly stablishing the theory that the Imagine Breaker can completely block esper telepathic communications.
 * Her name wasn't revealed in neither the manga, anime nor lightnovel, however she still received a name by Kamachi Kazuma.
 * In the anime, Yotsuba Voice Actress Yoshida Hitomi (吉田 仁美) is credited only as "Judgment".