After an unusual encounter with a peculiar demon, Hanae Ashiya's high school debut takes a bizarre turn as he finds himself confined to the infirmary due to the demon draining his energy. Discovering a flyer about exorcism by chance, Ashiya reaches out to the exorcist Haruitsuki Abeno for aid. Reluctantly, Abeno aids him in the enigmatic Mononokean tearoom, but not without a price. Strapped for payment, Ashiya reluctantly becomes Abeno's assistant to settle his dues. As days unfold, their dynamic shifts, unveiling hidden truths that reshape their bond and perceptions.