"Mushi": the most basic forms of life in the world. They exist without any goals or purposes aside from simply "being." They are beyond the shackles of the words "good" and "evil." Mushi can exist in countless forms and are capable of mimicking things from the natural world such as plants, diseases, and even phenomena like rainbows. This is, however, just a vague definition of these entities that inhabit the vibrant world of Mushishi, as to even call them a form of life would be an oversimplification. Detailed information on Mushi is scarce because the majority of humans are unaware of their existence. So what are Mushi and why do they exist? This is the question that a "Mushishi," Ginko, ponders constantly. Mushishi are those who research Mushi in hopes of understanding their place in the world's hierarchy of life. Ginko chases rumors of occurrences that could be tied to Mushi, all for the sake of finding an answer. It could, after all, lead to the meaning of life itself. [Written by MAL Rewrite]

Mushishi is an adaptation of Yuki Urushibara's award-winning manga of the same name. The series adapts the first 26 chapters of the manga, adapting one per episode. The anime aired these stories in a different order than that of the manga. The series won the Tokyo Anime Award in the Television category in 2006. The series premiered on October 23, 2005, but went on hiatus on March 12, 2006 after having aired 20 episodes. Broadcast resumed on May 15, and aired the remaining 6 episodes, concluding on June 19, 2006.