Haigaragakure was originally called Kinugakure, due to the clan that founded it, who had discovered a way to use silk as a weapon, and could weave silk out of pure air. Because of this, they became very wealthy, and the leader of the clan decided to found a village, hoping that it would bring them power and status.
But as they had chosen a remote location to build their village in, so they wouldn't be bothered by more powerful villages, not many shinobi joined, and within five years, all they had managed to amass was a total of fifty shinobi and two hundred civilians. Though this ensured that Kinugakure was left alone by more powerful villages, who saw them as no threat, it also meant that no one took them seriously, and they were left out of any major alliances. This angered many of their shinobi, and they began to search for ways to prove themselves as the best shinobi in the land so that others would be forced to acknowledge their status.
Out of all of these, there was only one clan other than the founding one: the Rikou, who all possessed high IQs, and were known for being very creative. Because of this, they were greatly respected, and their children were all put into arranged marriages to strengthen the village's political connections. However, twenty years after the village was founded, sixteen-year old Aimi Rikou, daughter of Kiyoshi Rikou, the clan head, fell in love and was impregnated by Gouzen Keji, a seventeen year old chunin. Knowing that she could not get rid of the baby, Aimi begged Keji to marry her to spare her the shame of giving birth to a child out of wedlock. To do this, however, Keji would have to prove himself more worthy than the man that she had been promised to, the son of the daimyo of the Land of Honey. To prove himself, Keji decided to slay the Eight-Tailed Dragon, that lurked deep within a cave near the village, believing that he would easily be able to defeat a mindless demon.
However, the demon was far stronger than he anticipated, and it nearly tore him apart. Keji managed to stumble back to the village, but the dragon followed him, burning everything in its path. When Keji returned, he told the village leader what he had done, and why. Furious, the leader ordered that the demon be sealed. As they were not part of the 'Bjuu Alliance' that strictly controlled which countries were allowed to have jinchuurikis, they were breaking the law, but the leader decided that it would be better to break the law and live rather than perish completely. As it was Keji's fault that the demon attacked, he was selected to perform the sealing on his unborn child. They tried to induce early labour on Aimi, but the dragon reached the village before they could, and so the demon was sealed within the child while she was still alive. Though they managed to stop the demon, it was at a great cost, as it managed to reduce over half the village to nothing but ashes, thus giving it its new name, and the sealing was unstable, allowing the dragon to take brief control of the baby. It forced the child to rip its way out of Aimi's womb, killing her, though she lived just in time to name the baby girl Kiyoshi, after her mother. The elder Kiyoshi denounced the child, and the most of the village followed. Keji's father was the only one who did not, as the village blamed Keji for the destruction that the dragon had caused and he hoped that Kiyoshi could salvage the family honour by becoming a good shinobi.
However, as the village had broken the law by creating a jinchuuriki, they could not allow any other villages to learn of her. Because of that, Kiyoshi was confined to the village, and ordered to not bring any attention to herself. To keep her amused, her grandfather taught her how to make seals, which were not considered loud or flashy. Because she spent most of her time on them, Kiyoshi was the most learned person in the village when it came to seals at the age of� nine - though that wasn't saying much - and she soon began to try and design her own. Because of this, her grandfather and grandmother were very proud of her, and were the only humans in the village to ever show her kindness.
One day, the grandparents decided to take a trip to Iwa, and they smuggled Kiyoshi out with them, so that she would get a chance to see the world outside the village. Unfortunately, they had a run-in with some Iwa ninjas who thought they were spies, one of whom was the Iwa jinchuuriki, who killed Kiyoshi's grandparents using the power of his bjuu. This both terrified and fascinated Kiyoshi, who saw the fear that the Iwa ninjas held for their jinchuuriki, and decided that she wanted to use that power as well, so that she would not be helpless or weak every again. When the Iwa ninjas had gone, she buried her grandparents and left the area so that she could find her own way to become strong.
Seven years later, Kiyoshi is working as a bounty hunter, who prefers to kill her targets rather than take them alive, as the pleasure the Eight-Tails feels whenever she takes a life is radiated through her body, giving her a temporary 'high'.
The Eight-Tailed Dragon
As her seal is flawed, Kiyoshi can hear the Eight-Tails speak to her. However, as it is not interested in anything other than staying alive, and thus keeping Kiyoshi alive, she sees it as the closest thing she has to a friend, and often talks to it. While the Eight-Tails is not particularly fond of her, it does talk back, often using complicated words which confuse Kiyoshi frequently, and it has remarked that Kiyoshi is its favourite host.
The Eight-Tails has a huge amount of chakra, second only to the Kyuubi's, and it also has extremely potent venom, which can cause death within a matter of seconds. No antidote has ever been found for it. It can also breathe a green fire that poisons as it burns, meaning that even someone of Tsunade's calibre would have difficulty saving them.