The story features ubiquitous creatures called Mushi that often display supernatural powers. Mushi are described as beings in touch with the essence of life, far more basic and pure than the grotesque creatures we are accustomed to. Due to their ephemeral nature most humans are incapable of perceiving Mushi and are oblivious to their existence, but there are a few who possess the ability to see and interact with Mushi. The Mushi depicted in the anime look very similar to floaters. One such person is Ginko, the main character of the series. He employs himself as a Mushi master, travelling from place to place to research Mushi and aid people suffering from problems caused by them.
(taken and edited from wiki)

Picture	Real Name	Description
	Ginko	Ginko's unusual white hair and green eye color is the result of an incident involving a mushi that occurred when he was a child. No explanation is given as to why his rather modern clothes do not seem to match the time period reflected by all other characters. Ginko is a rare person that attracts mushi, and thus the reason he wanders constantly. Staying in one place too long will gather a potentially dangerous amount of mushi. He also smokes constantly in order to keep mushi away. In terms of personality, Ginko is rather laid back, but can be very serious when it comes to protecting people from mushi. He also often stresses that the mushi are not evil, but merely trying to survive like everyone else.