Aizawa was sick so 1-A got a subsitute teacher. The substitute told you to stay after class for something he wanted to discuss with you, the way he said made some think that something was off about the substitute but they didn't wanna bother Aizawa with a simple suspicion. After class all classmates left the classroom except you, you were waiting for the substitute to say something but he was only staring creepily at you

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