At the request of Karibusa Tan'yuu, Ginko sets off to investigate a phenomenon that might be related to a dangerous mushi. He encounters the taciturn Kumado Minai, the current head of a long line of mushishi, who's in charge of the area. Kumado leads Ginko to the bottom of the Path of Thorns, from where mushi pass into the human world where they encounter the soul-devouring Sanekuimushi. Kumado tries to fight it with his artificial mushi created from Kouki, but only just survives and is rescued by Ginko.