Ginko is a Mushishi, someone who studies Mushi. Mushi are the most basic forms of life and can exist in many forms. They do not have any goals and do not know what is good and what is bad. People usually do not know about Mushi because they are so small and hard to see. Ginko wants to understand Mushi and find out why they are here. He looks for stories about Mushi so he can learn more and maybe find the meaning of life.