The nun's way of cleaning their bodies resulted in the orphan's awakening to BBW fetish, gloomy girls fetish, and a body-washing fetish. Which they never recovered from, for the rest of their lives.
Something that I noticed, that I think lends into the fairy/magic sort of aspect, is that the woman who has the dirty room seems to be from more modern times going by what's in it.
Pg.1 has a lamp on the nightstand near her bed.
Pg.1 & 2 have what looks to be beer or soda cans on the floor...
Funny to think that, since the store manager is the same person as from Muchi Maro's previous manga, that canonically the supernatural exists. The vampire MC also shows up in chapter 23 to support that.
Mangadex only has four chapters of it up but it's easy to find online if anyone wants to...