The logline of cat girls and cat boys that also transform into spooky witches and ghouls at night should pretty much sell itself. Everyone loves both of these things.
Here you are, a transfer student to Elsinore Academy, entering your final year of study, deciding who you will ask to the Spring Prom - and now having to deal with the mystery of why everything went all scary all of the sudden. For some reason, everyone thinks that you're the best person for the job in this adventure/mystery/dating sim/college sim wacky little video game.