Ginko (Mushi)

Ginko is the name of the mushi after which the protagonist of the anime series Mushishi has been named.

Description
The Ginko are silver glowing blind fish that swim within the dark mushi called Tokoyami.Repeated exposure to the light the Ginko gives off, turns hair white and turns eyes green. This is how Ginko got his name.

Prolongued exposure to the light of the Ginko will eventually cause a change in the creatures around it. One of their eyes will be lost to darkness (very literally), and the other will turn an unearthly green, while hair (or scales in the case of fish) while turn white. Eventually, the affected will become Tokoyami themselves, with the transformation starting in the one remaining eye and expanding from there. There is no known way to prevent this transformation, not even being kept away from the Ginko's light. While it can be delayed somewhat by unspoken means, this final change is inevitable once the hair and eyes change.

Plot
Before the start of the plot of the anime series, Yoki an 11 year old boy was swallowed by the Tokoyami, although he managed to escape but only after being exposed to the Ginko thereby turning his hair white and one of his eye's green. Yoki only remembered one name which was the name of the Mushi within the Tokoyami-  Ginko. After the Tokoyami was through with him. Yoki woke up the next morning being unable to remember anything but a name -Ginko, he then went by the name Ginko and became the protagonist of the series Mushishi.

Weakness
This mushi, living with the Tokoyami, they are weak to light.