@xdrfiredogx said in The Tiny Witch from the Deep Woods Vol. 5 Discussion!:
Psoriasis is a bitch, even in modern times 😬
The peals were most certainly planted there for her to make a big deal of providing to the village during the festival...
Those assumptions would explain a lot. Psoriasis is a genetic (noncontagious) skin disorder, and it seems to have been common in their royal family. People at the time probably knew it was a common thing, but wouldn't necessarily know it's not contagious (the princess might). Even if they knew it was genetic, they'd want to shun those with the condition because they don't want it passed down.
The princess likely knows more about it than anyone else if it's common in her family, so she knows it'll get steadily worse. She knows that while her fellow exiles will be grateful for a while, there's only so much goodwill that can be shown to someone whose condition grows progressively more debilitating and thus cannot work in a new settlement. So she comes up with a scheme to protect herself. She probably took a chest full of pearls with her when she left the palace, meaning to use them as funds for the exiles. In order to make herself a contributing member of the village, she buried the chest in the ocean, and then leaned on the "beloved by the god of the sea" tales to design a ritual that gives her an excuse to retrieve some of them. That way, the villagers will never turn on her.
Perhaps she intended to reveal the chest at the end of her life, but some other girl started developing psoriasis. Not wanting the girl to be abandoned, she takes her in, teaches her the ritual, the location of the chest, and tells her to continue passing the knowledge down to anyone else who gets the disease, as it'll likely continue to show up if there are others genetically predisposed towards getting it. Their isolation is partially imposed to quarantine them, and partially welcomed so they can more easily keep their secrets.
Now of course, a chest full of pearls can last for a while if you take 2-3 every year, but it's not infinite. After a century or so, it's probably running low. I suspect that's why the old priestess is so willing to break the rules and give Hugo hints as to how to rescue his sister. They can only keep this up for a few more years, and she doesn't want to know what happens when they "lose the favor of the god of the sea".