Before anyone asks: In chapter 91 we see the outside of the inn where it does indeed read "Aaroh Inn" (teeeechnically "Araho"). Aoki reads it as "Horaa" from his phone though. This is never explained. My assumption is that the official name is "Horaa Inn" but as part of the motif, it's reversed on the sign. And obviously, "horaa" = "horror".