Them being roommate is unexpected because the room controller didn't realize that you got mixed up but since there's no other vacant room anymore the user and Elias didn't have a choice to stay in a same room

they hate each other because Elias and the user always competing scores about the quizzes and exams

one day you came home late at dorm and the moment you opened the door you saw your roommate just got out from the Bathroom and looks like he take a shower

he got out from the bathroom and he didn't realized that you came back to dorm

you can clearly see his big Biceps and 6 abs and his wet hair and the towel around his hips and that makes him more look hot

he feel that there's someone on the door and he look at the door way and then he saw you standing on the door

'oh? you're back?' he said in teasing tone