Nigihayami

Nigihayami (饒速水琥, Nigihayami; Japanese for Amber Lord, or Amber God) is a shinobi who lives in Getsugakure, and was taken under the wing by Josho Adashino for training. He is treated as a jonin of the village, but officially has no ninja rank, having not been a ninja until he discovered several kinjutsu and was trained by Josho. He was once a scientist for Orochimaru, who informed on him to the Hokage, revealing his experiments. When the Konoha-Getsu Treaty Squad arrived in Getsugakure, he examined scrolls of Orochimaru's that Kojimaru Sensōkajiya had collected, and inadvertently became the victim of several kinjutsu. Due to exposure to dangerous gases while spying on Orochimaru, he fell into a coma for many years, and so appears, mentally and physically, much younger than he is.

History
Nigihayami was born into a world of blood, as Orochimaru used his father as a test for a poison that caused him to go insane, killing Nigihayami's mother and himself even as the newborn babe screamed next to them. He was sent to Getsugakure to be raised as one of them, due to superstitions about the misfortune of such a birth, and the Third Hokage's realizing that he would not be welcome in Konoha due to the circumstances of his birth. Eventually, when the Third Hokage began to look into the mysterious disappearances in Konoha, Orochimaru decided that he needed an assistant in another village to cull subjects without notifying the Hokage, and it pleased him to ironically choose Nigihayami, still a boy of only ten, whose life he had already shaped. Nigihayami, however, figured out from records of Orochimaru's what had been done at his birth, and ended up spying on Orochimaru and betraying him to the Hokage, resulting in Orochimaru's exile from Konoha. Remaining in Getsugakure, he took ill some time later, and after transport to Konoha's more advanced hospitals, where Tsunade, who had not yet left Konoha, treated him and discovered that he had been affected by gases in the laboratories where Orochimaru had made him work. Unable to completely nullify the gas' effect, she used all of her skill to counteract it slightly, placing him an extended coma and state of suspended animation rather than letting it kill him. She eventually decided that she was unable to save him, and left him in that state, rather than give up entirely. Eventually, when she returned to Konoha as the Fifth Hokage, she was able to use her much-improved skills to revivify him, reversing the coma and bringing him back the same as the day he had been placed under the coma. He returned to Getsugakure after pledging her his eternal servitude if she should ever need it.

Some time later, it was discovered through analysis of the gas that it could not have been completely removed, and he was recalled to Konoha for further testing. Indeed, it was still dormant in him, and Tsunade deduced that every seven years he would enter a similar coma-like state for one month, at which time he must return to Konoha. It was also discovered that it was warping the chakra in his left arm, though she could not predict how this would turn out. Once again thanking her, he returned to Getsugakure.

Years later, when he was twenty-two, the Konoha-Getsu Treaty Squad arrived in Getsugakure just as he was contemplating returning to Konoha for analysis of his arm, as it had begun to pain him, and sensory types seemed unnerved and wary when around him. Upon discovering that Kojimaru Sensōkajiya had been an experiment of Orochimaru's and had research on the Sannin's work, he decided that, rather than reveal his shaming debacle of the past fifty years, he stole into the house where the squad was staying and rooted through Orochimaru's work. Seeking to reverse the effects of the gas on himself entirely, he stole some papers and attempted several kinjutsu on himself. However, this caused a release of strange chakra, and sensing it, the Konoha ninja arrived to find him with the paper, and realized that he had stolen it. Explaining everything, Nigihayami was shocked when Kojimaru stated that he had come upon information about the gas long ago, but not thought it relevant to his studies. Ecamining the kinjutsu which Nigihayami had become the victim of, Josho deduced that they were permanent and irreversible, and began to train him as a ninja.