Some time between the Meiji and Taisho period... A mother and son walk through heavy rain. The son, YOKI, sees strange, iridescent creatures float from the mountainside and then disappear. He does not yet know such creatures are called "Mushi" and can not be seen by ordinary men. Suddenly, there is a landslide and Yoki's mother is swallowed by the flood. A Mushishi woman named NUI finds the child, who miraculously survived,
