Kakuriyo: Bed & Breakfast for Spirits Vol. 5 (manga)

Aoi has hopes that her time in Kakuriyo will mean more than just toiling to repay her grandfather's debt--she has a personal mission to find the yokai who kept her from starving when her mother abandoned her. Yet all she has to go on is the memory of a simple white-faced mask. She gets an important clue when a well-fed guest in a similar mask tells her it's a common souvenir from the southern lands. But how can Aoi go to investigate when a lone human in Kakuriyo is sure to become a snack for the first spirit to pass by?