It's surprising to see the lack of reviews for this manga, considering the fact that the anime boasts 56. Now, I've never seen the anime, so I don't know how it compares to the manga. However, I have read a large scope of manga, of many different genres, and I say this honestly: Mushishi is a masterpiece, a one-of-a-kind work of art, and the mangaka, Urushibara Yuki, is one heck of a storyteller.
The plot in Mushishi develops in a rather episodic format, rather like Natsume Yuujinchou or the anime Cowboy Bebop. Each chapter follows Ginko, who is a wandering 'Mushishi', a specialist who deals with 'Mushi', curious lifeforms whose existence may define the meaning of life. Most of the stories deal with Ginko coming across a mushi-related problem during his travels and solving it, however the story avoids becoming sluggish by occasionally breaking the flow with tidbits of Ginko's past. This change in focus offers us something more from this tale and keeps it interesting.
Despite what I said there, the mushi-of-the-week stories aren't something to fool around with either. Each are extremely original and varied, some happy and hopeful, some tragic, some bittersweet, and each with something to add to Mushishi's already complex kaleidoscopic world. Indeed, one of Urushibara's strengths is her ability to present clear storylines and sympathetic characters within the limits of each chapter without overreaching herself; Instead, she cleverly uses wide blocks of scenery and close-ups of conversations and monologues to create a slow languid narrative which, by the end, haunts you and lingers in your memory.
In this case, the art works well. With her pen Urushibara brings to life her bizarre mushi and the wild, earthy feel of nature. Except Ginko, everyone wears a kimono, setting the manga in rural Japan, complete with hills, swamps and rice patties. The style is between sketchy and solid, with clear lines and clean backgrounds present for the most of the time, while sketchy styles animate the wilderness of nature.
Character development is effective in this manga. The protagonist , Ginko, is truly a wonderful character. His calm and reliable persona is one, which I've yet to see in any other manga and it automatically puts you to ease as you follow him on his journey to discover more about mushi. However, although he is the protagonist, he is presented as more of a side character in the stories and it is the 'mains' (the people with the mushi problems) who are given ample focus to develop their personalities. While you may not remember all their names, you learn enough about them so that you want to know what happens to them, or even care about what happens to them. It's a powerful achievement, considering that most of the characters only appear once in the whole manga.
Ginko, on the other hand, is an enigma with his western clothing and white hair and green eye, and his character is developed only by a couple of chapters revealing his past and through his numerous interactions with others within the manga. While this could be a weakness in other mangas, it is a strength in Mushishi. Ginko's lack of background story allows more focus on the other characters, the mushi, and their problems. He acts unbiasedly, and only does what he thinks will be best for the people who ask him for help. While the manga follows Ginko, the story is all about the mushi and how they affect the world.
In the end, the story is about that: Mushi, life and nature. We see the effects that Mushi have on people and their lives. We see the array of their powers. We see how they coexist with nature. We see how we can mistake them for the supernatural. And we see how they can bring out the best and worst in us. If you are a fan of fairytales, the supernatural, or even slice-of-lifes, give Mushishi a try. I think you'll find it's graceful way of storytelling a beginning to an addiction.