According to animation studio, TOEI, the story of the newest One Piece movie will revolve around Straw Hat pirate crew battling their “strongest enemy yet”, a man named Z.

It was added that Z will be Luffy’s strongest enemy and a “heroic battle” between the two will happen in the movie.

The movie is set in the New World as with the current manga and the anime series. It was also announced that the movie, which is said to “surpass the Strong World” will premiere this December.

[Source]