The Demon Hag, おにばば, also know as Witches are fast runners.
She appeared as an old lady who'd fallen and sprained her legs, unable to move. She requested Nanami to help her to her house and as it was getting late, she invites Nanami to stay the night. She plotted to eat Nanami's flesh in order to live a thousand more years.
Nanami quickly figures out that there's something wrong with he old woman and escapes leaving a white talisman which spoke in Nanami's voice. The witch violently breaks down the door to Nanami's room, only to the find the talisman, the witch chases after Nanami and the will-o-wisp with her, Onikiri, she catches up quickly. Tomoe comes, only with the intention of watching Nanami cry.
Tomoe tells Nanami if she begs for his forgiveness, he would save her but, she refuses. She falls down and as she is falling she grabs tomoe's leg. as they are falling she kisses him, making him her familiar. Out of spite, Tomoe ties the witch to a tree, furious that he has to be a familiar underneath such a pathetic little girl.