The open-world One Piece game will not be limited to Japan. Moreover, it will end up on more platforms when it comes to North America and Europe next year. One Piece: World Seeker currently has a general 2018 release window for the PlayStation 4, Xbox One, and PC.
The Ganbarion and Bandai Namco game will have one player, offline action. The localizations will only have Japanese voice-acting. Players will follow Luffy and use his Gum-Gum abilities to traverse the open-world.
One Piece: World Seeker will come to the PlayStation 4 in Japan in 2018.