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".
This collection of stories, each with a unique viewpoint and moral, are some of the most brilliant storytelling I have seen in anime. Excellent dialogue and animation pull you into a world of the unseen mystery of life, with all of its beauty and fear, revealing joy and triumph, and the perilous things found deep in the human heart. Even though the stories are fictional works, intended to entertain, I see the natural worl around me so differently now -- that I am not so apart from the living world, as part of the whole. This anime provokes you into looking around and seeing what is there in ways you never thought of, and makes the real world much much more interesting. I highly recomend this anime.