Kahyō

is a member of the Ryūha Armament Alliance. She later becomes the warden of Hōzuki Castle.

Background
Kahyō and her older brother, Rahyō, were born in Kirigakure. Because her ancestors were conquered by Kiri, Kahyō was distrusted by the village and considered expendable. After Kahyō married, she and her husband chose to leave Kiri in order to escape this mistreatment. They settled in the Land of Waves, hoping to find freelance ninja work. Although they did indeed find work, they were no more respected there than in Kiri. Disheartened, Kahyō's husband turned to drinking and eventually drowned in a stupor.

With her husband gone, Kahyō stopped pursuing ninja work, instead choosing to support herself and her son, Hakuhyō, by doing odd jobs. The jobs were boring and didn't pay well, but Kahyō was satisfied because nobody got hurt. But one day, while Hakuhyō was playing in the woods with a friend, the two were attacked by hornets. Hakuhyō used the Ice Release he'd inherited from his mother to save his friend, not worrying for himself. The friend, scared of Hakuhyō's ability, abandoned him.

When Hakuhyō didn't come home that night, Kahyō went looking for him. She asked the locals for help but, having heard from Hakuhyō's friend about her Ice Release, they would tell her nothing. She eventually found Hakuhyō alone and in desperate need of medical attention. She tried to find a doctor, but all of the Land of Waves' doctors had been hired by the Allied Shinobi Forces to assist in the Fourth Shinobi World War. So Hakuhyō died, and Kahyō became convinced that no amount of effort would allow her to escape the world's cruelties. When the war ended, she and Rahyō joined the Ryūha Armament Alliance in the hopes of rectifying this.

Appearance
Kahyō has long, curly hair. Her shinobi-attire consists of snow-white clothes and a mask with a hook-pattern on it. In disguise, she wore a long, blue dress.

Abilities
Kahyō has shown to be a very skilled kunoichi being able to go head to head with Kakashi Hatake, the Sixth Hokage, and surprising him on several occasions. Her power was also enough to humiliate the Fourth Raikage in a training bout. As further testament of her skills, Kakashi recommended that she be put in charge of the Hōzuki Castle.

Nature Transformation
Kahyō is able to utilise the Ice Release, by simultaneously combining the water and wind-natured chakra to produce ice. Through the use of her kekkei genkai, Kahyō can freeze moisture in the air to form ice swords, which she can form from great distances. She is also able to freeze targets to death by causing ice particles to form on their body either remotely or through physical contact. The technique is very useful in neutralising shinobi and is on par with the Fire Release: Heavenly Prison.

Kakashi Hiden: Lightning in the Icy Sky
Naruto Uzumaki assaults the Armament Alliance's compound in the Land of Waves to capture Garyō, its leader. Kahyō tries to defend Garyō, but the Naruto she directs her attacks at ends up being a shadow clone. She realizes this in time to block Naruto from escaping with Garyō. Garyō tries to convince Naruto to let him go by, among other things, telling him how Kahyō's son died. Naruto shares his condolences, but it doesn't change his belief that the Armament Alliance's terrorist activities are wrong. Sai swoops down and, despite Kahyō's efforts to stop him, flies away with Naruto and Garyō. Two months later, Kahyō, Rahyō, and the rest of the Armament Alliance come up with a plan to have Garyō released from the Blood Prison by hijacking the Tobishachimaru, an airborne ship. Kahyō poses as a regular passenger in order to get aboard and is assisted by Kakashi Hatake, one of the Konoha-nin providing security. She plants ice particles on him in case she'll need them later. After the Tobishachimaru takes off, Kahyō secludes herself in a bathroom stall while Rahyō and the others begin the hijacking. When members of the security detail confront Rahyō, she remotely freezes them to death.

Kahyō hears someone moving in the air ducts running throughout the ship and attacks them with shards of ice. This dislodges the duct, dropping the person, Kakashi, in front of her. Kakashi recognizes her from their earlier encounter and believes that she is hiding from the hijackers. He takes her with him to find a safer hiding spot. Kahyō pleads with him to have Garyō released so that Rahyō will not need to kill any of the passengers as he's threatened to do, but Kakashi explains that he can't do that. He promises to save as many as he can before leaving her in an out-of-the-way location.

Kakashi and his cohort, Might Guy, soon set off exploding tags in an effort to force the Tobishachimaru to land, but Kahyō quickly stabilizes the ship and puts out the flames. She changes into her combat attire, dons a mask, and joins Rahyō, who is now fighting Guy and Kakashi. Kahyō trades attacks with Kakashi, who does not recognize her because of the mask, but does know who she is from Naruto's report about when he met her. Kakashi sympathizes for the death of her son, but argues that it is inevitable that a shinobi will lose somebody they love. Kahyō retorts that the deaths of fellow shinobi are one thing, but that the death of her son is an innocent life that can't be compared. Kakashi points out that the Armament Alliance is now threatening to kill the innocent passengers aboard the Tobishachimaru.

Kahyō becomes angry by Kakashi's observation and performs Ice Release: Earthen Consecutive Chains of Ice, which starts spreading across the area, engulfing everything it comes into contact with. Rahyō tells Kahyō to stop and, when his order is ignored, he knocks Kahyō unconscious. Though the Chains of Ice disappear, a hole is left in the floor and the different pressures between inside and outside start sucking out those on board. Kahyō's mask is blown off while this is happening, allowing Kakashi to see her face before he too is blown from the ship. When Kahyō regains consciousness, she plugs the hole with ice.

One of the passengers pleads with Rahyō to release her son, whose asthma is acting up and has lost his medicine in the hijacking. Rahyō contemplates allowing the boy to die as a form of payback for the death of his nephew, Hakuhyō. Kakashi reveals himself and pleads with Kahyō to let the boy leave with Sai, who helped him get back onto the Tobishachimaru. Rahyō, frustrated by Kakashi's return, attacks him. When Kakashi begins defending himself, Kahyō activates the ice particles she planted on him earlier to prevent him from using chakra. With Kakashi neutralized, she overrides Rahyō and allows the boy and his mother to go with Sai. When another passenger complains about this "special treatment", she freezes him to death.

Kahyō shares her history with Kakashi so that he can understand why she's doing what she's doing. Kakashi has no response to the cruelties that she's experienced or the senselessness of her son's death, and is silently taken away. As the Tobishachimaru nears the Blood Prison, Rahyō and the rest of the Armament Alliance begin outfitting the remaining passengers with parachutes, seemingly so that they can disembark safely. Kakashi, having escaped his confinement, confronts Rahyō, explaining to the passengers that the parachutes are loaded with explosives that will detonate when they reach the ground. He tries removing some of their parachutes, but the ice planted on him by Kahyō still impedes him.

Kahyō questions Rahyō about whether Kakashi's accusation is true, to which Rahyō reluctantly says that it is. Saddened, Kahyō attacks Kakashi but her ice projectiles miss and Kakashi, in his counter, discovers the ice binding him is gone. He attacks her, but stops short of killing her, realizing that's what she wanted. Kahyō admits that Kakashi's earlier words have been resonating with her, but only now has she become convinced that she was wrong. As she starts articulating her regrets, the Tobishachimaru begins to sway from all the damage it's received and a fire breaks out. While Kahyō focuses on extinguishing the flames, the ship heaves and Rahyō is flung overboard. Kakashi is unable to save him and Kahyō cries out in despair.

The damage to the Tobishachimaru causes it to rise higher and higher into the sky, which will eventually kill everyone on board. Kakashi convinces Kahyō to help him stop this and save the passengers by puncturing the helium sacs that keep the ship airborne. Once this is done, the Tobishachimaru starts plummeting to the ground and Kahyō uses her ice to hold the ship together and ease its fall. It works, but this rapidly depletes the moisture in the air until she can no longer make ice, at which point the ship starts tipping again. Kakashi leaps through a hole in the hull out into the clouds the Tobishachimaru is falling through and uses Lightning Release: Purple Electricity to induce rain.

Now able to make ice once again, Kahyō stabilizes the Tobishachimaru and lands it near the Blood Prison. Several passengers are injured in the crash, but none are killed. The Konoha ninja who converge on the wreck take Kahyō into custody on orders of the Fifth Hokage. Because of how many passengers died because of the Armament Alliance, Kahyō should be sentenced to death. But Kakashi proposes that Kahyō instead be given life-imprisonment on the condition that she become warden of the Blood Prison and use her ice to keep the prisoners in check. The Fifth Hokage agrees to this on the condition that Kakashi become the Sixth Hokage. Kahyō vows to accept this assignment if that is what Kakashi asks of her, so he officially takes on the title of Sixth Hokage.

A few months later, the Five Kage visit the Blood Prison to render final approval of Kahyō's position as warden. When Kahyō humiliates the Fourth Raikage by freezing off his beard, the other Kage decide that she is more than qualified. In time, Kahyō writes a letter to Kakashi, telling him that, although she is constantly busy with her duties, her heart is finally at peace.

Trivia

 * Kahyō is mentioned in Ultimate Ninja Storm 4 in a side quest in the Shikamaru's Tale Adventure Mode DLC. It is revealed that shortly after she took over as lord of Hōzuki Castle, the number of secondary offences within the prison had dropped significantly. As a result, Shikamaru suggests that Kakashi send her a gift to reward her for all her hard work.