So I have a few questions. 
1. If there is only one human, then how would the girls turn? Because in the anime there was only one girl and she hadn't turned much... though that could also be because a little someone someone didn't like her. Anyway, back to questions.
2. As there is a main character to every anime, how are you planning to incorporate the girls in the house as this anime is a reverse harem?
3. Is this Roleplay basically going to be singularly about this one girl? Or is it going to include different aspects as the Roleplay progresses? 
4. Based on the anime, would there be a school where no one knows of the zodiacs and will it include more humans? 

I just want to get the details before I make a decision on which to make.