Kazakiri Hyouka

She is Index's first "friend" in Academy City. She is gentle but shy. Not much is known about her aside from the fact that she was an overachiever at Kirigaoka Academy for Girls, according to Aisa. Her ability is Counter Stop (正体不明, Shōtai Fumei?, "Unknown Identity"). Details about her level are unknown, but it was mentioned that she was among the top psychics in the Kirigaoka Academy for Girls, though the Academy ranks the students by their ability's rarity rather than how powerful it is. It is later revealed that she is not a human at all but instead an algorithm of the psychic's AIM with a consciousness. 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.

When not physically manifested, she exists in a realm she calls 'the city of shimmers', a warped shadow of Academy City. This place is also called as District $$i$$ (or the Imaginary Number District).

Later on, another identity of Hyouka is revealed; in artificial angel mode, Hyouka acquires a halo with multiple rays emanating from it. In this form, she is referred to as Fuse=Kazakiri. According to Vento of the Front, in Christianity terms Fuse=Kazakiri is like a 'Fallen Angel' that has turned away from God, and is the most abominable being that can exist.

Aleister Crowley says Kazakiri, along with Last Order and Accelerator are all part of the 'Key' to the completion of Artificial Heaven.