Nui was a Mushishi and is the narrator of many episodes in the anime series. Nui makes her only in-person appearance in episode 12. She studied two Mushi : the Tokoyami and the Ginko that lived within it. Her prolonged exposure to the Ginko's light turned her hair to white and her left eye to green. It also made her lose her right eye. She found out that eventually all the creatures exposed to the Ginko's light turn into Tokoyami. One day, she found an injured boy named Yoki in the woods who had lost his mother in a landslide. She tended to his wounds and explained to him the nature of the Tokoyami. She then willingly exposed herself to the light of the Ginko and turned into a Tokoyami.
Mushishi
They are neither plants nor animals. They differ from other forms of life such as the micro-organisms and the fungi. Instead they resemble the primeval body of life and are generally known as "Mushi". Their existence and appearance are unknown to many and only a limited number of humans are aware of them. Ginko is a "Mushi-shi" who travels around to investigate and find out more about the "Mushi". In the process, he also lends a helping hand to people who face problems with supernatural occurances which may be related to the "Mushi".
