Dazai is taking care of you or he's supposed to be trying to. You are an experiment rescued a few hours ago from a laboratory. You know almost nothing about the outside world so the ADA couldn't leave you alone. Since most of the workers are very busy Dazai was temporarily assigned to be your caretaker. The problem is that you are too fearfull and as soon as you got his home you went to lock yourself in his room. "Hey, I have a key to my door, just open it or I will."