Mushi-shi

here's the main story of the REALLY awesome anime Mushi-shi courtesy of Wikipedia

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 similar to floaters, which the author most likely got the main idea for "Mushi." "Mushi" in the Japanese language actually mean "insect."

One such person is Ginko (ギンコ, Ginko?), the main character of the series. He employs himself as a Mushi master (蟲師, mushi-shi?), traveling from place to place to research Mushi and aid people suffering from problems caused by them. The series is an episodic anthology in which the only common elements among episodes are Ginko and the various types of Mushi. There is no over-arching plotline.