Responses
I was thinking that he might be who has them trapped in the dream and not the grandmother like Bihwan thought. Maybe the purpose of the dream is to "Save" the friend and since they failed to do that (we're show him getting beat up) time in the dream is going backward, basically the dream is starting over?
I should have really said spirit instead of boy lol it was a ghost that nobody else saw but minchan
I keep forgetting that a terrible incident happened to him in high school and that the friend in this dream is probably the friend who got seriously hurt or died