Kagura Reimeiki ~Mashiro no Shou~

A request for exorcism arrives at the Kirinomori Shrine.
The young exorcist miko, Mashiro Saeki, sets out to meet the client in a nearby town.

There, she learns from the local priest and his wife that yokai have begun to appear around the area, and the townspeople may soon be forced to abandon their homes.
While searching through old family records, the couple discover that, long ago, a powerful yokai had been sealed deep within the nearby mountain.

— Could that ancient seal have been broken?

Determined to save the town, Mashiro—still youthful in appearance but strong in spirit—takes up her sacred duty and ventures into the mountain where the darkness stirs once

[From DLsite English]