Damn, Twilight is really rocking that anime protagonist aura this chapter. Thinks the childhood friend was a boy and is dense as hell to boot, may as well make him the main character if this goes on any further.
Did some people forget that the demon world doesn't have daylight? It's always dark there. If anything, her putting up curtains is the weird thing because it wouldn't change much.
I just remembered that Suya isn't short. When they went to the human town, the demons were all really tall compared to the humans. So she should be normal height, right?