Pirate Warriors is an action game incorporating elements from both the Dynasty Warriors series and the One Piece series. The game's story mode, Main Log, allows the player to play through the storyline. The Adventure mode uses Luffy to play through the events of the One Piece series and the battle mode allows the player to use characters in battles. In Another Log, the player can play through a character's storyline. With it are several stories exclusive to the game

As with the rest of the franchise, Pirate Warriors follows the adventures of Monkey D. Luffy, a young boy who accidentally eats the Gum-Gum Fruit and organizes a diverse crew of pirates called the Straw Hats to search for the titular treasure. On his journey, Luffy makes several new friends, and battles a wide variety of villains.