Anime alternating normal life situations with darker and creepy moments

I'm looking for something structured with this contrast, of people that live normal lifes (e.g. high school students) and maybe transform into something weird at night, or their own environment is the one that transforms and live kind of nightmares and the next day turn again into the normal situations.

That is almost exact to the argument of Persona 3 but it doesn't have to be exactly that way. I'm very new to anime so I'm open to almost everything but I'd appreciate this contrast of realism and normal life with dark/creepy/bizarre/slightly gore moments.