As of now there is no harem (2 girls wouldn't be enough for the tag anyway, but that's an F95 issue, we know what we mean). However, you can get Emma and other girls, in fact almost all of the other girls, in the same playthrough (as of now Camila and Kylie are mutually exclusive). It just is a big hassle even for the more experienced players.
If you want a full harem, focus on Sam and Emma first, ignore everything else and get those two in order. You need to meet Morgan by going to the movies early, and you might want to get Sasha up to speed to avoid her blowing her ex (but then stop going home to not push her storyline too far) but other than that ignore everybody who is neither Sam nor Emma.
This means, NG+ is recommended because then you don't have to worry about money and can afford to not work for a while, accidentally setting off the Cassidy storyline - and Cassidy is the nemesis of Emma, so to speak.
However, Andrealphus said that Emma was too strict as of now in balance terms and there's gonna be a change some day.