I tried to watch a video of P5D and P3D, but it's so cringy... I got a bit further into P5D, but I just don't understand why they would accept a request like that.
That's part of my problem as well. The story is very weak, in my opinion.
The side comments are absolutely hilarious though. Like, when Ryuji finds out about all the female confidants, and even Yusuke grills Joker for details.
This game makes it clear that the PT crew has no idea who Joker all associates with, and I find that very interesting. If this story is canon though, it also confirms that Joker has no canon love interest, is an accidental flirt by saying bold things easily, and maxed all his confidants.
This game also takes place after the events of the main P5 game.
There are also more than 5 confidant levels in this game.
Once you break the 5th event, 3 more spawn. I don't know if more show up after that, as I havn't unlocked event 6 through 8 just yet.