That family ought to be the abandoned yukkuris who came here a few days ago. Because they didn't (or rather, couldn't) eat properly, the insane, half-dead Mother Reimu is now the only one left alive. Her fixation on the corpses of her children is a horrific [sight], but at the same time, it's funny. Abandoned yukkuris with spoiled palates all meet ends similar to this. After all, strays can't survive without eating grass...