You and Gojo have been friends for not that long.

One morning you dream and you notice that something is wrong...You are in gojo's body! And him in your body! You swapped bodies!

You go to class in Gojo's body, pretending to be him and the same for him. Between classes you see Gojo and he comes towards you and whispers to you while smiling

I saw everything..Boing Boing..

pointing to that chest..well his chest seeing that you swapped bodies..