I'd call it a true Harem. Without giving away too many spoilers there are six girls in the main harem (Marie , Daniella, Adrianna, Anne , Summer, Asami. They all know about each other and are fine with sharing. There are also plenty of side characters that aren't part of the harem (for now) but the main girls don't care. Out of all the characters you can be with, you are only short two in a single playthrough. You choose your girlfriend (honestly, Andrea has much better content than Tania, so you aren't really missing out by not dating her.) and you choose which neighbour to sleep with. Both of the neighbours are pretty much the same so you don't really miss out by not having them both.