Tokiwadai Dorm Supervisor

The Tokiwadai Dorm Supervisor or Tokiwadai Housemaster (寮監) is a recurring character in the Toaru Majutsu no Index series. She is the unnamed housemaster of the Tokiwadai Middle School dormitory that Misaka Mikoto and Shirai Kuroko reside in.

Appearance
She is a tall and slender woman who has shoulder-length brown hair and is often seen wearing her glasses, which often hides her eyes from view. Because of this as well as her personality, she is frightening to look at. She is also noted by Kuroko to be near the age where she'll be too old to be married.

Personality
As the housemaster of the Tokiwadai Dorm, she is very strict and has zero tolerance for espers who do not follow rules for any reason whatsoever. She also has no qualms in assaulting the students who are troublemakers, by snapping their necks and making them faint (though only Kuroko seems to receive this treatment). Generally, she has good command on the residents of the dormitory as well as the children of Cypress Park.

When volunteering for work in Cypress Park, she shows great affection for the children who reside there and is very easily approachable - a stark contrast to her nature as the housemaster of the Tokiwadai dormitory. She also shows great affection for Daigo, another volunteer in Cypress Park, where she can get easily flustered and embarrassed when he is near her.

Background
Not much is known about her background. All that is known is that she is the housemaster of the Tokiwadai Dormitory and that she is also a volunteer of Cypress Park, an establishment that caters on the welfare of Child Errors, and would go there every time she has a break from her duties.

Toaru Kagaku no Railgun
She receives a much more prominent role in the Toaru Kagaku no Railgun anime adaptation compared to the manga.

Level Upper Arc

 * Main article: Level Upper Arc

She first appears in Episode 2 of the anime, where her trademark neck snap is used on Kuroko after she is caught using her powers alongside Mikoto, she later punishes them to clean the pool.

Poltergeist Arc

 * Main article: Poltergeist Arc

She receives a prominent role in episode 18 of the anime adaptation. Here, she is stalked by Kuroko and Mikoto going to Pizza Hut and buying 10 boxes of pizza, they later discover that is a volunteer at Cypress Park and bought the pizza for the children there, they also find out that she is smitten for Daigo, another volunteer in Cypress Park. With the help Saten Ruiko and Uiharu Kazari, they were able to make various events for Daigo to like her, later Daigo admires her even more, after witnessing her command the children during a Poltergeist-related earthquake and saving a child from getting hit by a falling object. Daigo later calls her for some advice, much to her delight; here, he asks her for some advice regarding falling in love to older women, to which she misunderstood to be referring to her, and tells him that age does not matter, Daigo later thanks her for the advice. She receives a makeover with the help of Kuroko and the others in Seventh Mist, to prepare for the alleged proposal she will receive from Daigo. Much to her dismay, she discovers that Daigo is actually planning to propose to Shigenomori Kazuko, the principal of Cypress Park and a much older woman than her; even though she was heartbroken, she supported Daigo and wished him happiness. She later reverts from a lovestruck woman to her previous self, demonstrating this by once again snapping Kuroko's neck.

During Tokiwadai Dormitory's Midsummer festival, she brings the children from Cypress Park to enjoy the festivities and threatens Mikoto that she should do well in her upcoming performance. She is later seen listening to Mikoto's violin performance and is apparently content with it.

During a Fireworks Festival in Academy City, she checks on Mikoto and Kuroko and finds that they are busy studying, she leaves but then quickly returns to their rooms, nearly finding out that they were attempting to escape the dormitory to go to the festival.

She is last seen outside of the Tokiwadai Dorm building, lookin up at Kiyama Harumi's student's message for her on a blimp.

Daihasei Festival Arc

 * Main article:Daihasei Festival Arc (Railgun)

She reappears during Kongou Mitsuko's debut in the manga, telling and punishing Shirai Kuroko and Mitsuko for being too noisy near the Tokiwadai Dormitory outside the School Garden.

She reappears later in the arc proper, discussing the recent loss of Tokiwadai against Baba Yoshio's school with Watanabe, and opens up the possibility of punishing the students who were didn't want to get dirty during the course of the competition.

Sisters Arc

 * Main article: Sisters Arc

In the Toaru Majutsu no Index manga, during Kamijou Touma's visit to Misaka Mikoto's room, he hides underneath Mikoto's bed. The housemaster comes in and tells Kuroko that it is dinner time, she later asks Kuroko (who hid him underneath the bed in the first place) where Mikoto is, Kuroko then tells her that she maybe late because of extra lessons, to which she states that she has not received report of this and deducts she and Mikoto points.

Three Stories

 * Main article: Three Stories Arc

She is seen looking out of the window, grinning at Mikoto's defiantly rendezvousing with Touma just outside the dormitory, and seemed to be impressed with her.

Toaru Kagaku no Railgun Special 1: "MMR: More Complete Railgun"
She appears in the parody of the scene where she is first introduced, here she snaps Kuroko's neck three times  in a row , causing the lovable psycho-lesbian to scream "Abeshi!! Hidebu!! Tawaba", the signature death screams of the exploding villains in Fist of the North Star. She later reappears in a imagination scene as a soldier in the jungles, defeating people by breaking their necks whilst reciting nonsensical words.

Abilities
She has no esper abilities, though she is capable of stunning an esper by simply snapping their neck, as demonstrated by Kuroko. In an omake in the manga, she was also able to take down several members of the elite Hound Dog with relative ease, much to their bewilderment.

Trivia

 * The manga and anime of both Toaru Majutsu no Index and Toaru Kagaku no Railgun depict the housemaster with the same character design; however, only the Toaru Majutsu no Index anime has a different design for the same character and with a different voice actress (Okohira Shizuka), leading to speculation that the housemaster featured in the Toaru Majutsu no Index anime is from the School Garden.
 * She can whistle.