She is Index's first "friend" in Academy City. Gentle but shy, not much is known about her aside from the fact that she was a top student at Kirigaoka, according to Aisa. Her ability is Counter Stop (正体不明 Shōtai Fumei , "Unknown Identity"). Details about her level are unknown but it could be high, since it was mentioned that she was among Kirigaoka's top psychics. It is later revealed that she is not a human at all but instead an algorithm of the city's psychic's AIM with a conscious. The nature of her being leads her to be indestructible, as she can recreate any damage done to her body and lift objects several times her size, though she would cease to exist if Tōma were to ever touch her with Imagine Breaker. When not physically manifested, she exists in a realm called the Imaginary Number District which she calls 'the city of shimmers', a hidden dimension within the city.