Kishiko was an experiment of Orochimaru preformed after he left Konoha. She along with a countless amount of other children were injected with DNA from a blood thirsty man with bright green eyes who was believed to be able to recover from any wound and live forever, though he was dead, because someone had sealed his soul away. All children except Kishiko rejected the DNA and died in the process. After five years of observation with no signs of immortality showing up, Kishiko was deemed a failed experiment and ordered to be terminated. The girl went berserk and killed every one of the scientists. Impressed with the girl, Orochimaru let her go hoping the immortality would develop with time. Kishiko ended up in Konoha after wandering around a long time. She knew little of the world but quickly learned to steal in order to survive. Kishiko was eventually caught by the Jōnin, Nori Jinsoku, who lectured her, not knowing that none of it was being understood by her. Annoyed by the girl's lack of understanding, she adopted her and taught her to speak "just so she could scream at her". Nori was eventually ambushed and killed while on her first S-ranked mission. Kishiko eventually joined the ninja academy, wanting to make her adoptive mother proud. So far, the immortality gene has not shown up, but Kishiko has been shown to recover from crippling wounds rather quickly with little medical attention.