One of the best things about anime/manga games are the wide array of costumes. One Piece World Seekeris no stranger to this, with it containing a fair number of designs, but like a lot of things, it might take a while before you learn how to change into them. In fact, unless it is hidden in one of the many long, random and unneeded tutorials, I’m not even sure One Piece World Seeker tells you how to access costumes.
Before you gain access to costumes, you need to progress in the story to the point where you go to Thousand Sunny. This is chapter like three, though it shouldn’t take more than 30 or so minutes to get to this point. To speed things up, ignore all optional events and just go from objective to objective. When you get to the point where you’re supposed to find Chopper, use observation haki to determine his location and rush there. After that you’ll be asked to go to Thousand Sunny.
On the ship, head to the far right and the last door, to the right of the staircase, should give you the option to change your costume.
Upon entering, you’ll see all the costumes you currently have access to. Those who preorder should see the ironic bathing suit outfit and a special battle outfit. Since my copy of One Piece World Seeker was the deluxe version, I have access to the kung fu, hunter and white suit outfits.
After selecting the costume you want, you’ll return to the game wearing it. Not only does it change how Luffy looks in-game, it will also change your appearance during cutscenes and other story related events. And, once you get sick of looking at the costume, want a change or simply want it to look and feel like One Piece, simply fast travel back to Thousand Sunny and change costumes.