I don't personally get the impression that this game is about falling for one of the girls. The MC just got out of a failed long term relationship. This is purely about having lots of sex thus far.
I mostly agree with this poster, I also don't think it's time for him to start settling down, not by a long shot. As for the love part, it's already begun, if your paying attention to all the stories...
During one of Dani's events he flat out tells her if you select the correct choice "partial truth", that he did started this whole thing as a way to have tons of no strings sex, but has grown to care about all the women in the gym.
Also the way he talks to the girls you can tel he is getting attached to them, to varying degrees.
Maria - respect and fun
Amy - love and sex
Daisy - caring
Hikari - pride and caring
Dani - friendship
Sophie - love and gratefulness
Jenna - contempt and concern