Hysteria Savant Syndrome

Kinji in Hysteria Mode

Hysteria Savant Syndrome (Hysteria Mode or HSS) is a genetic trait which causes the bodies of those carrying the gene to activate 30 times more neural transmitters than the average person, which makes the function of his central nervous system, namely the cerebrum, cerebellum, and spinal cord, accelerate dramatically when he is sexually excited. As a result, in Hysteria Mode, logical thinking, judgment and reflexes all rise exponentially. Users enter a temporary super mode, like a transformation. It is seen in the novel that Hysteria Mode also permits the user to develop a sixth sense. Kinichi Tohyama describes Hysteria Mode as the ability to "use a gun to its fullest potential".

Known Users

• Tohyama Kinshirou
• Magane Tohyama
• Konza Tohyama
• Kinichi Tohyama (Kana)
• Kinji Tohyama
• Kinzou Tohyama (GIII)
• Kaname Tohyama
• Tooru Sayonaki (Vlad)
• Sherlock Holmes

Activation 

Hysteria mode is usually activated through sexual stimulation.

• Hysteria Mode's most common trigger is coming in sexual contact with women
  • Observing a woman that's dressed in rather exposing clothing can trigger it, albeit at a slower and more unreliable rate.
  • Kissing a woman instantly triggers Hysteria mode and has been noted to make the user even stronger
  • Kaname has suggested that Hysteria is caused through love and not sex (lust), possibly implying that the two can cause different effects. 
• Hysteria mode can also be triggered through endulging in a fetish
  • Kinichi can trigger his through crossdressing as Kana.
  • Tohyama Kinshirou was noted to grow stronger the less clothes he wore, indicating a stripping or nudist fetish.
  • Vlad's modified HSS is triggered by sadistic pleasure.
  • Kinzou (GIII) is triggered through an art fetish.
  • Kaname (GIV) is triggered through her love for Kinji, a brother complex
• Pornography is also a probable trigger as Kinji tries to avoid looking at that material and the erotic games Riko sends him to pick up for her while Magane has a special collection to keep his ability in good health.
• Hysteria Agonizante is only triggered when the person is on the brink of death, making it a special exception
  • Another exception is King Hysteria, which only triggers off of women associated with the user being in direct harm. 

Effects

• The user develops a hyperprotective manner towards girls, protecting them, speaking seductively to them and never hurting them no matter what happens. (At least, in Hysteria Normale.)
• Hysteria Mode can also alter the attitude and personality of the user, overriding emotions such as fear
• At its base, Hysteria mode increases the users mental, logical, and physical capabilities by 30

• 

  Kaname in Hysteria Mode

  Exclusive to Kinichi, his crossdressing trigger for HSS allows him to override the "harm no woman" restriction, but causes him to become an artificial persona of Kana.
• For women, Hysteria mode creates a weak and defenseless personality, which often causes men to be charmed and lower their guard.
  • It should be noted that the physical boost they receive from HSS is weaker compared to that of a male.
  • Female user can harm other women, but cannot harm men.

Flaws

Despite the massive power and potential Hysteria Savant Syndrome has, it does have quite a few devestating flaws to it

• Males under HSS cannot direcly harm a woman, even if she is attacking him. Though the man can evade and defend himself, he cannot keep it up forever. Kinji experienced this first hand against the Cao Triplets, which almost cost him his life
  • Conversly, Kaname, the only known female HSS user, cannot harm a man
• Though subjective, HSS drastically alters the personality of the user and the user will remember every second of it. In Kinji's case, he becomes a "terrifying gigolo" which embarrasses him to no end.
  • Upon ending her first time in Hysteria mode, Kinji noted Kaname's eyes were devoid of spirit as the actual nature of Hysteria set into her
• Hysteria mode can only last a few minutes at a time, although the exteremity of the trigger (such as kissing a woman opposed to her flashing the user) can make HSS last longer.
• Younger HSS carriers are more sensitive to triggering, in Kinji's case it left him scarred and developed a hatred for women due to them exploiting it.
• "Unrefined" triggers for HSS often have nasty side effects. In Kinichi's case, he can remain in HSS the entire day but afterwards falls into a coma for up to 10 days due to the tremendos stress HSS places on his brain and nervous system.
  • In addition to this, Kinichi "loses" his sense of identity during his cross dressing induced HSS. As noted by Kinji, he does not respond to "Kinichi" or "Nii-san" and only responds to Kana. 
• While HSS boosts neurological feats, HSS does not boost the user's physicality or constitution beyond the body's phyiscal limit. It is true HSS removes the brain's natural inhibitors thus allowing the user's true potential to be achieved, however it is not true that HSS gives super human speed or strength.
  • Furthermore, the meer fact HSS overrides the brain's natural inhibitors is a risk in and of itself. The body puts them into place to prevent harm, thus HSS overriding them can be greatly damaged from extending itself too much and the user could potentially face immense pain once HSS wears off.
• Through the use of the Wallachia magic flute and minor genetic mutation, it is possible to disable Hysteria mode via a hgh frequency sound impulse.
  • The affects of being forcefully removed vary, though a common affect is coughing up blood.
• Female HSS user like Kaname will tend to become weak and pathetic and stay that way for a period after the effects have expired.

Variants

• Hysteria Normale (Hysteria Mode): It's the normal Hysteria Mode, logical thinking, judgment and reflexes rise exponentially.
• Hysteria Agonizante (Near-Death Hysteria Mode): Those men that receive near-fatal wounds, will, before they die, feel an enormous instinct to leave their young behind, this is the Hysteria Mode under the influence of that instinct.
• Hysteria Berserk (1.7x Hysteria Normale combat ability at the cost of some of the logical thinking and judgments that regular hysteria mode gives): This Hysteria Mode is fueled by jealousy, triggered when the user sees a woman being taken away from him by another man. Hysteria Berserk accelerates, aggravates, and enhances the hate and jealousy that the user feels for other men, and is thus, is a very dangerous version of Hysteria Mode. Sometimes, the hatred and jealousy the user feels may spill over to women as well, allowing men in this version of Hysteria mode to harm women. In return for this, the user's battle prowess is increased to 1.7 times that of Hysteria Normale, but his thoughts will be completely focused upon aggression, so this too, is a double-edged sword. Though Hysteria Beserk will appear in unpredictable situations, it is not impossible to control. However, the first time is always difficult.
• Meza Hysteria (1/10 power of Hysteria Normale): If activates when you're starting of been aroused but something happens before entering Hysteria Normale and it stops in Meza Hysteria, while for a short amount of time the abilities increases only by a little.
• Dream Hysteria (Hysteria Normale) is the Hysteria Mode triggered when sleeping. It sometimes does nothing to do with the reality but the user can wake up in Meza Hysteria.
• King Hysteria (1.2x Hysteria Nomale) This state of Hysteria Mode is triggered when multiple close female associated with a Tohyama man is being attacked by an external threat. Though appearing weaker than Berserk, King possesses the unique trait of multiplying based on the number of women in danger thus potentially making it significantly stronger than berserk without any repercussions. 

Feats Performed in Hysteria Mode

• Accurately aiming and firing bullets into the barrel of the enemies' guns, effectively rendering them useless. (First used in the Segway Chase in Volume 1)
• Cutting a bullet in half with a knife. (First shown at the end of Volume 1 in the fight against the Butei Killer).
• Performing sword edge-catching using only two fingers. (First shown in the fight against Durandal in Volume 2)
  • In the anime, this was a sideways catch with Kinji's hands
• Shooting and hitting other bullets using the user's own bullets-- 'Billiard Shot'. (First shown in Volume 3 in the fight against Vlad)
• Derivative of 'Billiard Shot'. Bounces the enemy bullet back into its barrel, then uses the 2nd bullet of his burst fire to -- 'Mirror Shot'. (First demonstrated in Volume 4 against Kinichi)
• Kinichi is shown to be able to consistently swing his scythe at supersonic speeds. (Shown at the Volume 4 by  at the overwhelming fight with Patra)
• Catching a bullet fired at the user using his teeth. (Shown in Volume 4 during the fight against Patra)
• Kinichi 'Invisible Bullet' can only be used in Hysteria Mode.
• 'Ouka' - 'Cherry Blossom', By utilizing the incredibly fast reflexes imparted to him, the user is, for a moment, able to swing a bladed weapon at 1236 km/h, which is faster than the speed of sound. However, the attack is a double edged sword, as it causes massive damage to user. However, the attack itself is unavoidable, and cannot be dodged by any means. However, it can be defended against in other ways, such as through use of Edge-Catching. Only usable under HSS, due to the need for the enhanced reflexes that it imparts to the user. (First used in Volume 5 against Sherlock)
• Following the acquisition of Desert Eagle and Scramasax, Kinji can now dual wield his weapons when in Hysteria Mode, rendering him as the third known Quadra in the series. (First shown in the decisive battle against the Cao Cao triplets in Volume 7)
• Slash, a derivative of sword edge catching. Using four fingers (both left and right forefingers and middle fingers, respectively), Kinji performs edge-catching in right hand on a bullet. However, unlike a blade, it is not possible to catch a bullet using edge-catching due to velocity and its small size-- all it does is divert the flight path slightly. Following up another edge-catching in the left hand, the slash technique is completed. As a result, he can successfully parry a bullet by diverting its trajectory diagonally using fingers. Kinji named the skill after the symbol "/", by the manner of how the bullet was deflected. (First shown in the decisive battle against Cao Cao triplets in Volume 7)

Trivia

• It appears that the Tohyama's, the main carrier of the gene, are leaders of justice, strength and law as Kinji describes that his family has worked the guardian jobs for generations.
  • It is mentioned by Vlad that there were indeed other carriers of HSS, but for an unknown reason the Tohyamas are the only bloodline to not go extinct.  
• Interestingly, Kinji had developed another, personal derivative of Hysteria Mode he dubs as "Hysteria Wiseman Mode". This mode allows him to remain unaroused for a fair enough length of time. However, this method of protection for him is imperfect. He cannot maintain this mode for very long if the sexual arousal level in the room he is currently in keeps increasing. (This mode only makes an appearance in the Blu-Ray Side Stories and is therefore not applicable to the actual series.) 
• Based of the real medical condition savant syndrome