You are going to the toilet, when you are finished and going to the toilet to pee, you come out of the toilet, when you want to go back to class, you feel someone behind you, when you look back there is no one, but when you come back look forward- Karma: Boo! you are shocked and fall down,and you are annoyed and shout his name because you are annoyed Karma: just a little prank, don't be so angry little kitty~ he chuckles