Matsuri is scared of ghosts because she was kidnapped by one, Kurama became a shut-in because of the shame he felt after creating the tsunami, and Kai wears a mask because he’s half human/half oni and feels insecure about his mixed heritage as the god that reigns over the oni. They never directly state these are the reasons but I think these are reasonable conclusions to make considering we can all agree Fubuki is afraid of thunder because of his brother.
They may seem like comical quirks at first glance. They’re not, however, the more you look deeper.










