Kantarou Ichinomiya has lived with the ability to see demons since childhood, which led to social isolation and bullying. He developed a strong bond with the demons and began to see their existence as meaningful. The legend of the ogre-eating Tengu, a powerful demon, caught his attention, and he became determined to find and meet it. This led him to take on work as a folklore writer and demon-buster to fund his search, which eventually led him to a local shrine said to be the Tengu's seal.