[@PKMNB0Y]

Let's just say that his signature costume gets trashed during his transport to the real world and due to that, people assume that he's actually David Bowie.

EDIT: Besides, I've watched Re:Creators before (i'm a big fan of it!) and from what I have seen, characters can exit their respective works of fiction at any period of time as long as there's some sort of interference. He could get pulled out at the period of time wherein his suit got thrashed by Josuke and friends, and if that happened, people might really assume that he's David Bowie. 

It sounds ridiculous, but ridiculous happenings are my thing.