Check the door on the left corridor "CAMERA"(Not your office door)is closed.
When it's opened, Misty(shark girl) can hear your plushie noise.
If you awaked her and heard her scream, shut your left office door immidiately to block her, but you loose much of your sanity when she slammed the door.
Also, always keep your sanity higher to touch plushie often when you are free so you can 2~3 touch each to make it almost full. And don't look camera too much because while you can't touch plushie.