Kamen Rider My-Th arrives at a certain mansion pursuing a mysterious shadow attacking people. In that mansion, nestled deep in the forest, "Yokai" lived quietly... "It's hard to live in the human world. Humans label us as villains." What does My-Th witness in the mansion? Humans and Yokai. The line between them is now beginning to blur... And at the same time, another "red shadow" was creeping up on the mansion...
