The game's plot revolves around Rocky Hattari who has challenged Luffy and Straw Hat Pirates to a "Treasure Battle" to win their treasure. Luffy agrees to the challenge, the treasure in question is a card collection.
There is a special competition called the "Treasure Battle" clash which is being hosted in the Grand Line on a special series of islands. The Blue Berry Time newspaper is covering the events via Rocky Heart. The Straw Hats, along with Vivi and Ace, should trust each other and work together in a group made of two members and battle through various events to get Treasure Cards. The Treasure Cards are said to give the possessor happiness and can make wishes and dreams come true. The Straw Hats, Vivi, and Ace decided to compete. Luffy and Vivi pair up together. Zoro and Ace, who were not interested in the treasure but their competitive sides are rubbed, so they join "just to win". Sanji followed Nami, who is joining for the treasure. Chopper was amazed hearing that Usopp had a plan. Thus, the teams were decided.
- Mr. 2
- Don Kreig
- Miss All-Sunday
- Rocky Hattari
Story mode. There are 4 stories to choose from:
- Luffy and Vivi - 'Easy mode'.
- Zoro and Ace - 'Normal mode'.
- Sanji and Nami - 'Hard mode'.
- Usopp and Chopper - 'Very Hard mode'.
The player will fight 3 Treasure Battles in a row, then have a special mini game for the 4th, and then a best-of-3 round Treasure Battle for the conclusion.
A Treasure Battle is a fight between two teams. The team that can succesfully carry a treasure to a goal, preventing the other team from taking it until time up, wins. After winning a Treasure Battle in the story mode; players get a Treasure Card.
The player chooses the stages and characters.
"Treasure Battle" is a (two-player-in-each) team game, and has players grabbing a treasure chest and putting it into a boxing ring at the end of each island level, then literally waiting for their ship to come in. Once their pirate ship arrives, that team wins. A team can throw the chest to each other over a limited distance, lob it in the direction they are facing over a greater distance, or even use it to attack the members of the opposite team who are doing their best to grab the treasure chest and take it back to their own boxing ring, and their awaiting pirate vessel.
The screen is split in the "Treasure Battle" according to how many human players are involved. In one-player mode, the full screen allows a decent view of the action, but the 2- and 4-player splits reduce the action to an extremely small view that can make it very hard to determine what is really happening.
"Battle Royal" is a similar game to "Treasure Battle", except there is no chest and the arena is more confined. Each team just bashes the opposition about, as much as possible, for just under 3 minutes. All players are displayed on the full screen, which will zoom in and out depending on the spread of the action.
Kung Fu SurvivalEdit
"Kung Fu Survival" both teams are placed on to a very small island inhabited by large numbers of Kung-Fu Dugongs. Whichever team beats up the most dugongs within the time limit wins. The player can walk right up to a dugong and attack it in the face, or if they choose Zoro they can have him attack with a kendo. The dugong are basically defenseless, but if a player is standing motionless, may wander over and attack with a headbutt or flipper strike.
Team Work RallyEdit
"Teamwork Rally" has each team passing the chest to each other across gaps that can't be jumped over whilst carrying the chest. The race to the finish is a careful balance between taking risks to get the edge over the opposition and being careful at other points to avert disaster.
"Cross Country" is an individual race to the end of each stage of a longer race. Each player gets a score based on their position at each intermediate stage and the team scores are totaled at the end of the whole race. The race is conducted along a series of different jumps, ladders, islands and narrow passageways.
"Pirate Soccer" is pirates playing soccer. Except the ball is enormous and can crush the players if they fall under it. They have to use their attack moves to push the ball through goals at each end. Each half is 90 seconds.
"Treasure Hunt" has players wondering around randomly until an arrow appears, directing them to hidden treasure.
- The game presents Rocky Heart, a non-canon character present only in the game. Rocky talks a lot in English and plays guitar.