Her humble pretense as a wheelchair-ridden woman belies a nature fitting that of a Kihara. She is one of the members of her family ordered by Academy City to attack Baggage City and destroy the Natural Selector tournament held by the Anti-Academy City Science Guardians.
As a member of the Kihara family, which follows a nomenclature redolent of science and mathematics, Byouri's name can be translated as Pathology.
Other than the obvious wheelchair, Byouri's appearance is that of a woman with tea colored wavy hair, tied up in a ponytail. She wears pajamas, as if she was a patient of a hospital. One of the most recognizable characteristic she has is her blank brown eyes, which is often seen nearly covering the entire cornea.
Byouri hides her true nature with a facade befitting with that of a kind and helpless woman. Her true, bloodthirsty nature matches that of a true Kihara, as she has no problem with killing people off, evident in her attack in Baggage City. To complement this trait, she is also terribly devious, capitalizing upon her weak-looking nature.
In her own words, she refers to herself as someone that is good at giving up. She indicates that she has given up on many things, and thus forces others to do the same.
Byouri has implanted herself with Equ.DarkMatter, and thus Kakine Teitoku's presence lingers within her, persistently attempting to reject her consciousness and assume control over her mind. Kagun conjectures that this present threat effectively prevents her from using her power freely.
Byouri's Psychopathy and Bloodthirst even extends towards her own relatives, as seen where she possessed little to no hesitation in attacking her relative Kihara Enshuu even after she helped her, simply due to the fact she turned her back on her while in mid conversation. It was also revealed that she also holds both contempt and disdain for her two relatives Kihara Kagun and Kihara Nayuta due to their kind hearted natures and their care for others and prioritizing their safety over their scientific advancements, believing that such behaviors to be unbecoming of those born into the Kihara Family. Byouri herself even went as far as hatching a complex scheme resulting in the deaths of several innocent children for the sole sake of forcing Kagun to "Give up" on being a teacher that ultimately ended up being the prime reason for her death at Kagune's hands.
As part of her nature, she has apparently forced several people to "give up" on their dreams and ambitions. It is unknown on how many other things Byouri herself has relinquished.
Three years prior during spring, Byouri plotted to coerce Kihara Kagun into giving up his role as a teacher, as she considered the occupation unbecoming of a Kihara. She prepared a student erased from records, as to corrupt and manipulate him into giving up being a teacher. Byouri succeeds in her effort, as Kagun kills the student pawn and resigns as a teacher, although she may not have anticipated Kagun's departure from Academy City.
In the wake of the invasion of Hawaii, she, Ransuu, Enshuu, and several units of armed Academy City personnel infiltrate Baggage City on November the 13th and launch a full-on terrorist attack on the city.
Shinyaku Toaru Majutsu no IndexEdit
Baggage City ArcEdit
- Main article:Baggage City Arc
She first appears right after Marian Slingeneyer brutally massacres several Academy City operatives. Here, she introduces herself as a weak wheelchair-bound woman, although, Marian discovers this shortly thereafter, and attacks her. Marian is later surprised by Byouri's ability to maneuver herself in a wheelchair. Byouri engages Marian with her mechanically enhanced wheelchair, which forces Marian to transfigure the bodies of the Academy City personnel she killed earlier into her form to dodge Byouri's assault.
As the battle continues, Byouri reveals that her wheelchair can have legs, making herself more maneuverable. However, Marian later dominates her by bending the legs of her wheelchair, and later cornering her in the burnable garbage area, near a pit for garbage to incinerated later.
With her wheelchair stuck, Byouri is forced to use the machine on her legs that allow her to stand up. Byouri takes a machete-like blade from the back of her wheelchair and tries to attack Marian. However, due to her quick thinking of calling Academy City reinforcements for Byouri, allowed her to use their living bodies for transfiguration, and from there catapults Byouri into the pit, leaving her for dead.
She manages to survive however, and meets up with Kihara Enshuu, who helps her out of the trash compactor pit. With no choice left, Byouri is forced to use her trump card and activates her Equ.DarkMatter implants, taken from Kakine Teitoku. Here, she grows wings from her knees and thighs allowing her to walk. After being lectured on the nature of the Kiharas, Enshuu turns her back on her. Byouri takes this opportunity to attack her, reasoning that it may bring out a better Kihara if she is lost. Surprisingly, Enshuu notices this and uses the thought pattern of Kamijou Touma to attack her, Enshuu later leaves her with bloodied hands.
Still though, Byouri survives Enshuu's attack on her and is able to discover that she has been defeated by Kumokawa Maria, Saflee Opendays, and Oumi Shuri. Here, she tries to attack them after transforming again from afar but is unable to, as a helmeted man appeared, forcing her to attack him, though, his helmet is destroyed, she finally discovers the true identity of the masked man, Kihara Kagun. Here, he reveals that he has manipulated events, in order for Byouri to lose all of her safety devices, as proof that he had killed her, as so he can fight her on the same level. Kagun blames Byouri for corrupting the attacker of his students that forced him to kill him in front of them. The attacker was a pawn prepared by Byouri many years ago, in order to force Kagun in giving up becoming a teacher that is looked up to, someone who is so unlike a Kihara, and now redemption for him is to kill her.
With her projectiles, Byouri attacks Kagun, but he was somehow unscathed by the accurate attacks. Kagun then reveals his power, a laser blade that he held between two fingers. Here, he severs Byouri's transformed arm, which Byouri manages to transform again, to that of a large furry arm. She tries to crush him with the arm as he was standing on an elevated level, but is once again unscathed, and uses his power to pull Byouri down to his level. Byouri continues to attack with both her Skyfish and Yeti forms, but to no avail, as Kagun simply cuts the Yeti arm apart. While being preoccupied on how Kagun gaine his powers, he attacked her head, destroying the brain. However, because of this, it activated another form of her powers, Little Gray, and Byour's limbs began to expand as if inflamed. An explosion occurs and engulfs Kagun, and Byouri is completely deformed due to the use of her powers. However, Kagun survives, though his clothes were rip apart, telling her that he will never be damaged. Byouri realizes that Kagun may be a part of GREMLIN, and may be using laws that are outside the realm of science, an alien landscape for a Kihara. Realizing that Byouri cannot kill him immediately, she resorted on giving him light injuries to bleed him out, which Kagun realizes. Kagun reveals his power, the Whitting, a sword that scatters when its owner is at a disadvantage, creating a miracle, allowing the wielder to avoid damage accurately, and cause the sword to be sharper, and when it is reassembled, the sword's destructive power increases exponentially. Kagun questions why Byouri did not use her power until the end, and conjectures that she may be losing herself due to the 2nd Level 5. 
Suddenly, Byouri transform again into Loch Ness, forming into a giant monster. Seeing this, Kagun reveals that he is not planning to win, and would rather have a stalemate were the both of them die. An explosion occurs, and the both of them fall into Maria's path, and here, a severely injured Kagun stabbed Byour's monster head, and wrenched it off clean from its body.
Magic God Othinus ArcEdit
- Main article: Magic God Othinus Arc
In the final recreation of the world by Othinus created specifically to break Touma's spirit, known as the Version_Omega world in-text, where several characters from the original world have been "saved" or have not experienced great tragedy, the Kiharas, as there are apparently no dark experiments in the perfect world's Academy City, chafe at the peace. This exemplified with Enshuu and Byouri's conversation, both alive in the perfect world. Byouri says that as a Kihara peace is so boring. Enshuu replies that it doesn't matter if it is good or evil as long as they can play around with science they might as well live in a way that fits this place (the perfect world). Byouri then talks to Enshuu about a project they have been asked to do: research and develop a new standards for garbage disposal. Byouri comments on how that job won't even take them three days to finish.
As a last resort, Byouri has her Equ.DarkMatter transplanted into her. However, she requires authorization to use it, as there is a threat of losing control. In the arc, she has Enshuu hold it for her. The most common attribute of this power is her ability to recover quickly from injures as well as allowing her to use transformations, these transformations can be used at the same time. All these transformations are named after cryptids, or creatures whose existence has not been proven
- Base Form - This allows her to heal from any injuries as well as allowing her to walk, an aftereffect of this is Byouri growing wings from her knees and legs.
- Reference: Skyfish - Based on the cryptid known as the Skyfish, barbs or darts form on Byouri's arm, allowing her to use them as a projectile. It is compared to that of a metal nail, can pierce through metal containers, and can be fired accurately from 1000 meters away.
- Reference: Yeti - Based on the Yeti, Byouri's arm changes into a large and furry form. It has tremendous strength, allowing her to crush metal containers with ease.
- Reference: Little Grey - Based on the Grey alien found in popular culture, a tremendous change occurs to Byouri, where her limbs expand as if inflamed, and can be described to being as large as a toddler's scalp. This change was once considered for use by Academy City residents, as it primarily served as a function to build the brain, though it was a failure. Here, Byouri's right and left arm respectively turn to that of a giant's arm and a five-brained monster. Byouri can use the power of this form at Level 2 or Level 3, and with it can cause an explosion and can peel off flesh and blood from the bone.
- Reference: Loch Ness - Based on the Scottish legend of the Loch Ness Monster, is the last known and most extensive transformation Byouri has. Simply put, Byouri changes her entire body into that of large dinosaur-like creature. Byouri is still able to communicate in this form.
She has no powers, but is still very dangerous. Her wheelchair is “Made in Kihara”, presumably since it was developed by the Kiharas. Her wheelchair contains a light machine gun and cannon with a caliber great enough to fit a human arm, as well as a machete-like weapon. Furthermore, Byouri can transform her wheelchair into a walking mechanical carriage, like a spider, allowing for more maneuverability than that of her wheels.
Finally, if there is a need, there is a special technology installed on her legs. From the back of her knees, something like a plastic machine wraps around her legs, looking more like ribbons than armor. This allows her to make use of her legs and gives her enough strength to kick a tiger to death, apparently through a motor in the back of her knees. Marian identified it as some powered casts for hospital patients she had seen in a commercial before, but Byouri answered that had merely been what could be created without Academy City's technology, stating that it would be a bad idea to give her version to patients. Byouri later called it a leg assisting robot.
Character Art DesignsEdit
Byouri's design in the character sketches is more subdued compared to her appearance in the illustrations, indicating that she is outside humanity or has some kind of monstrous aspect to her.
- (To Marian, from NT4): “I, Kihara Byouri, am a pro at ‘giving up’. I have given up on all sorts of things myself and I have made others give up on all sorts of things. So give up, Gremlin.”
- (To Marian, ibid): "...Those who are hated must put in more effort and skill than those who are popular to survive this far. Humans grow the most when they stand up to difficulties."
- (To Kagun, ibid): "But...A Kihara that helps people. A Kihara that children look up to. As the one that gave up right away, that is a troubling possibility, isn’t it? As you are a representative of us Kiharas, I needed you to give up too, Kagun-chan.”
- (To Kagun, ibid): "Oh, dear. Now this is a problem. It seems you still have not given in, Kagun-chan. The one you want to protect is not that attacker who is already dead, is it? It does not matter if it is someone you see has hope within Kihara like Nayuta-chan, someone from Academy City like Kumokawa Maria, or even outsiders like Saflee Opendays or Oumi Shuri. That is the type of teacher you were. So make sure you give in this time. Making others give up is the one thing I will never give up on as the one who gives up on everything."
- (To Kagun, ibid): "This is a Kihara. We use science as a base humans exist on, use these methods and create breakthroughs through areas that far exceed expectations. Can you understand the essence of it?"
- ↑ 1.0 1.1 1.2 1.3 Shinyaku Toaru Majutsu no Index Light Novel Volume 04 Main.11
- ↑ 2.0 2.1 2.2 2.3 2.4 Shinyaku Toaru Majutsu no Index Light Novel Volume 04 Main.31
- ↑ 3.0 3.1 3.2 Shinyaku Toaru Majutsu no Index Light Novel Volume 04 Main.30
- ↑ 4.0 4.1 Shinyaku Toaru Majutsu no Index Light Novel Volume 04 Sub.15
- ↑ 5.0 5.1 5.2 5.3 Shinyaku Toaru Majutsu no Index Light Novel Volume 04 Period.21
- ↑ Shinyaku Toaru Majutsu no Index Light Novel Volume 04 Period.32
- ↑ Shinyaku Toaru Majutsu no Index Light Novel Volume 09 Chapter 7 Part 2
|Kihara Amata||Kihara Gensei||Therestina Kihara Lifeline||Kihara Nayuta||Kihara Kagun|
|Kihara Ransuu||Kihara Byouri||Kihara Enshuu||Kihara Yuiitsu||Kihara Noukan|