Yea...Kidding...right

Loads of people joke about suicide...but sometimes the joke isn't as funny as it's made out to be. (Y/n) is one that jokes all the time, you can never find her being serious...unless it's about suicide...but of course no one notices since she always smiles. But they noticed when she left. They think she's dead...but is she? I'll give you a hint...she's not the one that's dead...she does the killing.