The protagonist can take an art course at Kosei High School like Yusuke. And getting into a different reality can be done like this: You need to draw a certain door (with special symbols or something like this), after passing into which the group finds itself in a certain lobby (As in P4). Throughout the game, the protagonist team will confront another group of persona-users, who will steal known paintings using a parallel world. Although with these opponents real rates will not be felt, so later a group of opponents may begin to kill people they dislike for any crimes against real art (for example, Madarame). It would also be nice to play as female. Not for the ubiquitous femenism, but simply because why not. Of course, this is not the best idea, I don’t deny it. It's just my fantasies about what may be the 6th part and that's it.
I hope my english isn't extremely terrible.