Mushishi
Complete | urushibara yuki | 2000 released
It is my favorite manga so I am biased, but this story has a way of telling human stories even with a supernatural twist. A child with horns, a bog-woman, snow that keeps following a grief-stricken man, a tree that lives for hundreds of years. All of these stories are touching, heartbreaking and so human, that they leave you feeling melancholic and nostalgic for something you have never experienced. Highly suggest reading this manga.
Monster and the Beast