Each episode has a different tale, with the only reoccurring character being the main character, Ginko, and the reoccurring theme being about the Mushi. The Mushi are described as being lifeforms that are pure and closer to nature than any other lifeform. They are ethereal, and display an endless variety of otherworldly powers. Because of their form, very few people are able to see and interact with the Mushi. Ginko himself is a Mushi-shi, or Mushi master. He travels Japan in search of new Mushi to add to his research and helps cure people who are ill from exposure to Mushi.
The quality of this anime is extraordinary. This is really the first time in a long time that I actually paid attention throughout every single episode of an anime. Each episode focuses on a different Mushi, and the people it has affected. The creativity behind the stories is just amazing, it really is quality at its best. Stories range from a Mushi that makes one's eyes burn in the light, to one of a Mushi that brings great harvests in exchange for a person's life. The show is very emotional, and makes you connect to the people that are affected by the Mushi. By the end of each episode, your heart strings will have been pulled quite a lot; the beautiful and somewhat sad soundtrack adds to this effect.
The art style is also very good, adding to its effect and creativity. It really adds the emotional and surreal feel to the Mushi and the environment. I particularly like Ginko's design; he is very simple and relaxed but everything about that seems to make him an enigma. All in all, I highly recommend that you watch this anime right now; its definitely better than all that shounen crap that's still popular.