I won't say that Jump Force is a perfect game. It has some issues, and I don't find myself rushing to play it, but it's still a great game. DeviantArt user ogami4 decided to spice things up with some nude mods.
First up is the Boa Hancock nude mod. She and Kaguya from Naruto make up the current total of female playable characters. [A bit of an update. This was a joke. There are in fact FOUR female characters in Jump Force: Boa, Kaguya, Rukia, and Galena. Carry on, citizens.]
Finally, but with no picture, is the breast physics mod. The effect may not be very good, according to ogami4.
All said, great mods that should make this game better. I doubt anyone would get away with these mods in online play, so please don't try it. I ran into a player named Big Tiddy Goth GF, and that might have been pushing it.
If you want to skip the mods and go straight to the action, there's plenty of doujins from Boa Hancock's series One Piece found HERE.