One hundred years ago in Japan, a mysterious life form called "bugs" was popular. It was invisible and colorless, and almost did not belong to any family, but it could have a huge impact on human spirit and body. Ginko (Odagiri Joe), a white-haired and one-eyed man, was born with a special physique. He could sense the existence of bugs and use this skill to help people solve their problems, so he was also respected as "Mushishi". Ginko traveled through mountains and rivers and encountered "Amu" who ate sounds, the girl with four horns, Zhenhu (Moriyama Reia), the legendary dream rainbow "Rainbow Snake", and the "forbidden bug" that must be sealed by transcribing the story of the bug... In the process, Ginko was inevitably affected by the bug... This film is adapted from the original work of the same name by Japanese cartoonist Urushihara Yuki.