One Piece Premier Show 2018 was held at Universal Studios Japan and ran from July 6, 2018 to September 30, 2018.
The Bounties Pirates, Prize and Bounty, have the goal of getting the highest bounties in history and decide to kill all of the kings at Levely to achieve it. The Straw Hat Pirates meet Igaram Jr., who looks exactly like Igaram, on an island and are asked to save Vivi. They must stop the Bounties Pirates from using a poison gas bomb, developed by Caesar, before they carry out their attack. Buggy and Buggy's Delivery, including mercenaries Mugon and Dandy, also appear to fight the crew, and events from the Arabasta Arc are reviewed.
The show begins with a review of the events from the Arabasta Arc, with the Straw Hat Pirates fights against the Baroque Works agents and the clash between the Arabastan Royal Guard and the rebels. Two years later, Vivi and her attendants are traveling to Levely. The Bounties Pirates are also on their way, with Bounty planning to kill all of the kings in attendance to reach his goal of a 100 billion bounty. Kaidou is supporting the crew, as he wants to see the seas fall into great warfare. However, the Bounties Pirates discover that Caesar Clown has been kidnapped, and they need him to make poison gas bombs to kill the kings.
The Straw Hat Pirates dock on an island with a variety of clothes, an abundance of food, and lots of pretty girls. Sanji is about to sit down when a News Coo arrives with a letter. He is disappointed to find it is from Duval, who is on a tour of the New World and hopes to run into the crew. He tears up the letter, and Karoo walks up to them to the crew's surprise. Behind him is a man who resembles Igaram, Igaram Jr. The two have no blood relation but have the same appearance, voice, and weapons. Igaram Jr. reveals that he took Caesar's heart and kidnapped him to prevent the Bounties Pirates from attacking Levely. Lower members of the Bounties Pirates arrive to retrieve Caesar, and the crew fights them off.
The pirates report back to their other captain, Prize, about Caesar's whereabouts with Luffy. Prize becomes angry and attacks them when they inform him that they failed to capture the scientist. He confronts the crew himself reveals that he at the Deri Deri no Mi, a fruit that allows him to deliver things to any place he can see, even things that are invisible to him. He sends a virus at the crew, causing them to cough uncontrollably. Buggy and his Buggy's Delivery members Mugon and Dandy appear, fighting Luffy, Zoro, and Sanji respectively. The Bounties Pirates summon a gatling gun from the ocean that sprays seawater, weakening the Straw Hat Pirates' Devil Fruit users. Bounty attacks Luffy, and Luffy sneezes, falling into the ocean. Usopp jumps in after him, and Prize uses his Spear Delivery to remove Igaram Jr.'s heart and gives it to Caesar. The Bounties Pirates attack the Thousand Sunny and leave with Caesar. Usopp rescues Luffy and takes him to the Thousand Sunny's sickbay, where Chopper works to find a treatment for Prize's virus. Chopper cures the entire crew, and Sanji calls Duval on a Den Den Mushi, asking for help. The crew and Duval pursue the Bounties Pirates on watercraft.
At Mary Geoise, the kings receive a statement from Bounty detailing his intentions to kill them all. The kings try to evacuate to a ship, but they begin to panic and fight each other. Vivi tries to calm them down, and she helps a slave girl who was being abused by a World Noble. The crew catches up to the Bounties Pirates, and Usopp, Nami, and Robin find the cannons the Bounties Pirates planned to use for the poison gas bombs, disabling them. Bounty fights Luffy and gets the upper hand when Crocodile appears, who came with Daz Bones to steal Caesar's poison gas bombs.
Back on Mary Geoise, the kings continue to fight each other until Vivi's voice breaks through, demanding that the fighting stop. They listen to her, but a World Noble shoots a gun in the air, ordering that he should the first to board the evacuation ship. The World Noble puts his gun to Vivi's head, but Sabo and Koala appear and knock him away.
Buggy, who had been with the Bounties Pirates, confronts Crocodile and is blown away. Bounty finally falls to Luffy's Gomu Gomu no Red Hawk, but Prize begins provoking him, inspiring him to get up. Zoro and Sanji attack Bounty, causing him to fall for good. With the cannons disabled and Bounty defeated, the crew believes they have won, but Prize reveals that he can use his ability to launch the bombs without the cannons. He throws a spear, which Luffy catches with his bare hands, and then he throws one of the bombs. It will reach Mary Geoise in ten minutes, so Crocodile proposes that they knock Prize out in that time to stop his ability. Mugon and Dandy block Zoro and Sanji and fight them again, defeating them. Bounty gets back up and fights Luffy again, and Luffy gets knocked into the ocean again. Duval and Igaram Jr. rush to rescue him, but Bounty knocks Igaram Jr. into the water in the process. With only one minute remaining, Bounty declares that the Straw Hat Pirates have lost. Luffy activates his Gear Fourth: Boundman and attacks Bounty. The pirate does not fall, but he is moved out of Luffy's way while the young pirate attacks Prize, knocking him out and causing the poison gas bomb to fall into the ocean before reaching Mary Geoise.
With everyone saved, the crew sees Vivi across the water, and Igaram Jr. retrieves his heart. The show ends with the crew and Vivi raising their left arms as a sign of their hidden friendship.