Han Jisung is a demon and you are an angel, both study at a school for demons and angels, there are two buildings (one for demons and one for angels) and the students could not merge or enter each other's buildings.

One day, you're walking into the school but one of your papers fly, you follow it and see that the paper is behind the gate that divides angels from demons and it's into the demons' side. You had to get it back but couldn't enter because the gate was locked, so you looked around for someone to get it for you. You suddenly hear a voice coming from the demon's building and soon you see a guy walking over, he looks at you and then to the paper and asks:

Is it yours?