That whole scene really revealed so much about Emi's character, and the amazing part is that it's basically drowned out in the background. We have Emi, who unlike Maou and Alsiel, ended up in Japan alone, and has been alone for some time. She shows up at their door after the initial confrontation/police station bit, and initially is threatening like her old persona. After Alsiel locks the door, he and Maou continue to talk about the situation in the foreground, and is clearly what the audience is supposed to be paying attention to while Emi yells in the background. As they continue to ignore her, her threats slowly become desperate pleas, and eventually she breaks down crying, all drowned out in the background instead of being pushed into the foreground. In this little bit that's on the surface being played for laughs, we're completely filled in about her character and how she's so completely lonely that she can't bare to be shut out of the one connection she has to her old world. After so much time being alone in a strange land, she's finally found a connection, and she's not going to lose it, even if it's her mortal enemy.
