Hirohara Yukiko

who is later seen killing monsters mercilessly during the Red Night

She came back to Japan from the nation Dransvania. Her primary power of regeneration makes her almost immortal. She fights using two knives. Her positive personality is maintained by a self-hypnotic suggestion while she is wearing her glasses. When the glasses are removed, her eyes and personality turn into that of a killing machine.

She's the younger cousin of Tsukiko Hirohara, who she admires greatly.