The entire game is harem.
No it is NOT, Carol begins calling you her BF, without you even discussing it, and after a certain point with NO WARNING you declare you LOVE Roxy, without the option to say otherwise, at the cost of fun times with someone hotter, her sister. Roxy starts talking about wanting to meet your family, and Rachel TAKES YOU to meet hers.
That is not Harem.
Harem is crazy, absurd, convoluted story reasons as to when you can bang both Nat and Roxy, at the same time... and even as a THREESOME.. yeah the best ones cross that line, to which I say HELL YEAH.
Harem is not Carol just assuming you are BF/GF now... but asking can she maybe, possibly, if it is OK, maybe.. see.. if we would mind if she thought of me as such, maybe.... and begging, if asked to... whilst we are given the option of agreeing, declining, or compromising by offering another nature to our relationship ranging from 'Exploring more than Friends" to 'Sl*t, you're my service animal and nothing more, and be thankful your even that".
Harem is exploiting the precarious situation with Rebound Rachel, and using the ethical boundaries crossed by her entering in to a sexual relationship with her student, to make her your dirty little secret, who accepts being such, and your having fun with younger college girls.
Harem is actually being ABLE to chose choice two Natalie gives you if she finds out about you and Roxy if you got the Roxy path, but even more harem is an option which allows you to somehow force Natalie in to being a FWB DESPITE you doonting Roxy too.
This game is not finished, and might never be, but if it IS, then it will be a Romance game, I guarantee you. All the fun you have NOW with the girls, will come back on you.. and you will at BEST have to choose a Carol/Yuki path, Ashley/Sara path, Rachel path or Roxy path. The writing is on the wall. Once Yuki starts her new social club to circumvent the rules around her message business, she will be in more intimate private contact with Sara and Ashley than she already is... and you and HER, or you and Carol WILL come out.... likewise, with Sara getting closer and closer to Rachel, they will learn about each other. I am sure there will be story beat that essentially means Roxy will find out about ALL of them too.
Then you will HAVE TO CHOSE.
That aint Harem.