The current plan is to not hard lock you into any specific path outside of you not being able to be in more than one place at a time. Your choice of how you spend your day will inform how your relationships develop and what kind of content becomes available. Even if you end up committing to one character down the line, I don't plan to block off going to hang out or hook up with other dudes. Just, depending on the guy you committed to, he may not be very pleased about it.
So just a quick example of this: After the first day of classes, you'll have the choice of where to spend your afternoon, evening, and late evening. You might go to Matt's apartment in the afternoon, then a party in the evening, and either stay at the party late or head back to your dorm room. In this intro you can promise to hang out with Matt after the first day of classes, but it doesn't mean you're locked into being with him that whole next day. However, if you break the promise or leave the hang early, it will affect your relationship.
All of this involves many, many flowcharts, but I'm a big fan of reactivity and choice in my games, so I'm gonna do my best to make it not feel too railroaded :)