One Piece: Romance Dawn marks the first game in nearly 15 years, eight games and five movies that will get release on the PSP. Yeah, you read that write: PSP, not Vita. So the chance that this game is going to be Japan only is pretty high. In fact, that would all but be confirmed due to the content of Romance Dawn following an alternate opening for the One Piece franchise.
While Monkey D. Luffy still ingests the Devil Fruit that makes him made out of rubber, Romance Dawn is sort of a "What If?" storyline that focuses solely on him, the Red Pirate Shanks and going on adventures instead of hunting down treasure. Even the original one-shot video made for the title is a half-hour and the basic structure of One Piece came from Romance Dawn.
Andriasang highlights the game's RPG nature, focusing primarily on Luffy, as he handles enemies with a system similar basic RPG elements showing tables to select actions like Fight, Flee and Use Item. To see the original scan from "Weekly Shonen Jump" head over to Gematsu.