My first presumption about the story is that we enter into a wrong hotel room or she enters into our room, and she catches us there, jumping into hasty conclusions, blaming us being a underwear thief or some other sort of miscreant up to no good.
Or then she lures us in the room, then falsely accuses us for laying our hands over her, trying to blackmail us into paying up hush money.
And ending presumptions are as such;
Rape - We are indeed a panty thief or a stalker, or punish her severely for the false accusations and rape her into silence / obedience.
Lewd - Same as above but fuck/brainwash her into becoming willing participant, JSK has hinted about PSI Ojisan making a return, hence the brainwash.
Enko - We offer to pay for the goods, and give little extra if she lets us take it further, pretty much the same ending as with Yua, since JSK confirmed this ending is coming back.
Love - We or she entered the room by mistake, she apologises for accusing us and reveals she has ran away from home for reason or another, wants to make up for the mistake and offers sex as apology to show she regrets what she did and we offer to give her a place to stay, and one thing leads to another.
I am of course totally going to be wrong about this by the time the game is released and we all can laugh how wrong I was about the plotline this time around.
But if I happen to get it right, then I'd better start filling out lottery tickets.