Interesting demo. I very much like what I have read about this game. It seems probable that it will be very intriguing, with the numerous character dynamics, story, multiple routes, and a variety of endings.
In terms of possible additions to the demo, you might consider adding in a bit of extra interactions or dialogue with the other characters.
Will the ally-rival factor in the full game have a menu page showing those relations? If such a thing exists, it could be interesting to make it show up in the demo, even if nothing else about the mechanic appears.