The mother of a boy named Shigeru visits Mao's clinic, asking him to examine her son. Mao goes to see Shigeru, but it turns out to be a trap to lure him out. A water-manipulating shikigami attacks, attempting to capture Mao

Entrusted with a message for Mao from a cat demon that appeared in the Reiwa era, Nanaka heads to the Taisho era. Hyakka and Kamon are visiting Mao's clinic. Kamon reveals that the one running the fraudulent business under the guise of life extension was Shiranui, a water sorcerer.