They didn't exactly remember, Naomi just had a deep sense of De Ja Vu. She didn't actually have any memories of being there until she got there, I believe. Just a heavy sense of that time/place setting.
Pewds! Play with the voice acting! We all love your voice acting but I heard the voice acting is better in Book of Shadows than in the first Corpse Party and I would love to experience it even just once to see if what I heard was true! Love you and STAY AWESOME BRO! *brofist*