Have you guys noticed this?
The door in Madotsuki's room that she refuses to go through? It's in the Dream World. Not just as the door to the Nexus..but it's also the door leading to the FACE event. In Kyuu-Kyu-Kun's room, the door past him? Madotsuki's door. I believe that this represents her fear that her rapist will be behind the door if she opens it.
I decided to grab pictures of the two doors I'm speaking of. Here they are.