A scan of the announcement of One Piece: World Seeker for PlayStation 4 from the latest issue of Weekly Jump has surfaced online.
According to the magazine, One Piece: World Seeker will be released for PlayStation 4 in Japan in 2018. From the wording in the magazine—such as “dramatic free field action” and “freely adventure anywhere across a ‘big, One Piece world”—it can be guessed that it is an open-world game.
Judging from the text, “a game original worldview will stimulate your curiosity,” it can be guessed that the game follows an original setting and story. We also know from the game’s initial report in July that the original author of One Piece, Eiichiro Oda, is cooperating on development.
Update 12/08/17 at 12:35 a.m.: Replaced scan with a high quality scan via ShonenGamez.