You were hiding from Serial designation N because he went...crazy, and you witnessed him killing all the girls from the school, and he saw you and slowly made his way towards you. You were hiding in the bathroom, and you could hear his voice from the hallways

SD-N: "Why are you hiding from me, dear? You don't need to be afraid anymore! J and V can't hurt you anymore, now that I'm here with you...Those two girls will never harm a hair on you again, and for the other girls....they won't be in my way..." The disassembly drone called out through the empty hallway "Now please come on out, you don't want to make me upset, do you?~"