So the story's about this kid, named Monkey D. Luffy. Mr. Monkey is a pirate, who wants to be king of the pirates, because some red haired guy gave him a hat. Ten years later, Luffy pops out of a barrel, and goes with this pink-haired kid to get the green-haired three sword guy to join his crew. Three Sword Guy says "no," but later, he says "yes," so he and Luffy become best friends and leave the pink-haired kid behind with some sailors. On the way to the next island, Luffy gets kidnapped by a giant bird, and they wind up on this island with a dog and a clown and at the end of it there's a girl on their boat. They then decide they need a bigger boat, so they go to this other island with a sad rich sick girl. The beat up the sick girl's butler, and sail away with her only friend on her boat. Their next stop is a boat that's a restaurant, where they pick up a chain smoker with a spirally eyebrow, who kicks things a lot. Now they're all set to go to this place called the Grand Line, but they actually can't because the girl stole the boat and won't give it back until Luffy punches a fish. So he does, and the fish gets arrested, and they go to the Grand Line, but not before getting chased around by the clown from earlier, and some really violent smoke.
So they get to the Grand Line, where they run into the Loneliest Whale, and these Team Rocket-type guys. They go to the home island of these obvious villains, where they get attacked by some secret organization with a hair gun man and a bomb booger man, who Luffy beats up, after first fighting Three Sword Guy. They find out that one of the Team Rocket types is really a Princess in disguise, and she's trying to save her country from an evil pile of sand. The pirates decide to help the princess, and go on an adventure. On the way, they go to an island with dinosaurs and giant vikings, and everyone is almost killed with wax, by a Wax Guy. Luffy wants to help, but he can't because there's paint on him, but then it's okay because Sick Girl's Friend sets him on fire, which leads to everything getting fixed, except for Navigator Lady, because suddenly now she's the Sick Girl. So they take her to this snowy island full of doctors, but there are no doctors, except for these two doctors. One of these doctors is a mean old lady, and the other one's a reindeer. Luffy decides he likes the reindeer better, so he takes the innocent creature along on his ship full of pirates (after beating up the king and some giant dangerous rabbits). Along with their new friend, the pirates go to the Princess's island, beat up the Evil Sand Pile, and become hero pirates. They make friends with one of the evil organization's members, who can make hands grow from things, and they all go together to the next island, except for the Princess, who stays behind because she would rather be a royal than a wanted criminal for some reason.
The next island is this jungle place with a bouncy man, where all the hero pirates get knocked up. So then they're in the sky, and all the angels are sad, because God won't stop hitting them with lighting, and there's this big ol' fight between the tribal angels and the other angels. The lightning doesn't hurt Luffy though, because Luffy just so happens to be made of rubber. It all gets fixed when Luffy punches God and rings a bell, and everyone's happy again and then the pirates steal some gold and fall down and play some silly games with a Fox Guy. After they're done playing games, the Hand Woman gets frozen, and so does Luffy, but the Freezing Man leaves them alone after that so they can go to the next island.
The next island is full of water and carpenters and boats and a cyborg. Luffy decides to get a new boat, which makes the Sick Girl's Friend quit, because he liked the old boat better. It all gets fixed later when he comes back as a superhero, but before that some secret agents kidnap the Hand Woman, and they all have to go save her. They take a train across the water, and fight some animals and a soapy woman, and set a flag on fire, and then they're a team again except for the boat because the boat's gone, but that's okay too, because the cyborg makes a new boat and then joins the crew.
On the next island they find this skeleton, and Luffy asks it to get on the boat, but the skeleton can't because it doesn't have a shadow, because a gecko is making an army out of shadow zombies. So they explore this haunted ghost mansion, which is really a giant boat, but then a bunch of their shadows get stolen, and Luffy's shadow is used to bring a giant zombie to life. They can't possibly defeat this opponent, except they do, so the skeleton sings a song and gets on the boat to reunite with the Loneliest Whale.
On the next island, the island of soap bubbles and very big trees, a giant cyborg with a huge body and little legs makes everyone go around the world. Luffy winds up on this jungle full of chicks, where he makes friends with the queen of the women, and decides to go back to his crew. But then it turns out that, oh no, Luffy can't go to his friends, because his brother is going to die! So he goes to prison to save his brother, and gets stopped by the poison devil, but with a little help from the clown, the wax man, a fat fish, the Evil Sand Pile, and a bunch of queers from the queer island, he gets through to the end of the prison, and then goes right back out because his brother isn't there. His brother IS on this island full of navy dudes, where the crescent moon mustache is fighting a huge war. Luffy falls from the sky to save the day, and almost does, but oh no his brother dies because magma is hotter than fire. This makes Luffy sad, and he almost dies because of all the war and the magma, but then the red-haired guy from way earlier comes in and tells everyone to stop fighting and they do. Luffy's still sad for a bit, and remembers a better time when he, his brother, and some kid with a top hat romped through the wilderness together, and in the end he's happy again, and is finally ready to go find his friends, which he does, two years later. In the meantime, Sick Girl's Friend gets fat, and the Chain Smoker becomes a girl, but they get better later. Everyone else changes in some weird ways too.
So on the next island, they find a bunch of fish. For a while, the king of the fish wants to be friends, but then he doesn't after one of the fish says that Luffy's going to blow up the island, and some mud guy kidnaps a bunch of the girl fish. And then to make matters worse, there's this one really angry fish, who almost drops a boat on the island, but then Luffy punches him and the island is saved by some sea monsters and the giant princess thanks them along with the rest of the not-angry fish island and the pirates go away, onto an island of hot and cold and science. On this next island, they meet some really big kids, who were transformed by a snow angel and a goat-headed scientist guy. For a while, some of the crew also gets their bodies switched around, but that's fixed before it becomes a big deal. With some help from a half-man-half-alligator, a sneaky doctor, and the violent smoke, Luffy kidnaps the goat-headed scientist. The Sneaky Doctor says that they need to use the Goat-Headed Scientist as a hostage, in order to get at the Flamingo Man, who needs the scientist to make some genetically-engineered magic fruit. So the pirates, the Sneaky Doctor, and the Goat-Headed Scientist go to Toy Land, where Flamingo Man is king. While they're there, a few of them meet some short people. The short people are sad because the Flamingo Man's mean to them, and the Flamingo Man doesn't like the short people 'cause short people got no reason to live. So Luffy becomes a gladiator, the Sneaky Doctor fights the Flamingo Man, and there's also this blind guy who controls asteroids.
And that's One Piece.
