From the raws, Cheong-rim doesn't rape minimart while he's high (I think). He actually waits for minimart to sober up and gives him a haircut while he is out of it.
I think it mc transported to his younger self which transported to the novel or transported in a parallel universe where he is in the novel and sent back BEFORE the novel even started. Pick your poison.
That schlong should be classified as a weapon cause wtf