Hishigata Hirumi was a high school student at Seiin High School, already deceased before the series' main events. Her body was resurrected through necromancy, becoming a central figure in a complex plot after being possessed by the evil spirit Taowu. She had long hair styled into twin tails. Initially, she appeared minimally clothed and directly connected to a large number of wires and pipes. While alive, she wore her school's uniform. Her background involved being a normal student around the time Esther Rosenthal was tricked into participating in research led by Hirumi's brother, Mikihiko Hishigata. Despite this, the two became friends. After her death, Esther's attempted resurrection resulted in Taowu possessing Hirumi's body, a fact her brother refused to accept. Throughout the Necromancer Arc, Hirumi did not speak in the manga until near the end, though the anime adaptation altered this. She was primarily seen connected to life-support systems while her brother and DA pursued their goals. Mikihiko Hishigata's actions were motivated by a desire to help his sister achieve Level 6 status, believing the perfected esper formula would benefit her. His deep love for her was demonstrated when he physically blocked an attack meant for her body, and he initially refused to believe she was truly gone. The possessing entity was eventually revealed to be the evil spirit Taowu, which housed the will of Isaac Rosenthal, Esther's ancestor. After the installation of the Sister's network data was completed, the entity first pretended to be Hirumi before ceasing the imitation and revealing its monstrous nature once Mikihiko was mortally wounded. In her final moments, after Esther exorcised Taowu using Emperor Shun's Blade, the last remnants of Hirumi's consciousness briefly surfaced to say goodbye to her brother. Following this, her corpse crumbled to dust. Beyond the main series, the character appeared in other media. In the mobile game *Toaru Majutsu no Index: Imaginary Fest*, both Hirumi and her brother were among the deceased seemingly revived in Academy City during an event called "The Return." She also made a brief appearance in the short *Tobidase Ippou-san Hachamecha Kaishingeki*, cheering on her brother.