Yukiko Hirohara

A lively girl who is later seen killing the monsters mercilessly during the Red Night. She is a granddaugther of the Hirohara zaibatsu, one of the richest house in the 11eyes world. She came back to Japan from the nation Drasuvania. Her power is regeneration that is way above the ordinary human level. She fights using two metal knives. Her positive personality normally is maintained by self hypnosis which she planted suggestion for herself using her glasses. When the glasses are removed, her eyes and personality turn into that of a killing machine. She is one year younger than Yuka and Kakeru.

(Source: Wikipedia)