If you're looking for anime similar to One Piece, you might like these titles. All recommendations are made by Anime-Planet users like you!
Index is still a fugitive and many powerful magical organizations and individuals want to take her to use the books in her memory, eliminating her in the process. War between those organizations is also starting to emerge. Index can only rely on her friend Tōma, who has always protected her, along with Misaka and other friends from the Academy.
The foundation of alchemy is based on the law of equivalent exchange; you cannot produce something from nothing. As such, alchemy is bound by one taboo - human transmutation. Four years ago two young brothers, Edward and Alphonse Elric, broke this taboo when they tried to resurrect their dead mother. During the process Al's body disintegrated and Ed lost his leg. In a desperate attempt to prevent his brother from disappearing completely, Ed sacrificed one of his arms so he could affix Al's soul to a suit of armor. When his missing limbs are replaced by auto mail parts, Ed bears the name of the Fullmetal Alchemist - the youngest ever State Alchemist and dog of the military. Now, alongside his brother, Ed uses his status within the military to attempt to find any way that he can return their bodies back to their original state.
There's an adage that one man's trash is another man's treasure; but for Kosuke Ueki, one man's trash is another man's... tree?! Junior high school teacher Mr. K is in the running for the title of Celestial King. Candidates must select a junior high school student to endow powers upon, and then the students might fight each other mercilessly. The victorious student's benefactor will become the new Celestial King! Kosuke was Mr. K's choice, and for his power, he chose the ability to turn trash into trees. Furthermore, if he uses his abilities to harm others, he will lose one of his natural talents. Now, Kosuke must battle a variety of other power users to help Mr. K win it all, all while keeping his talents intact!
While at first glance these anime seem nothing alike, I couldn't help thinking of One Piece as a watched Law of Ueki. I think Ueki (the main character) reminded me of Luffy (the main character of One Piece.) Both of them punch before they think and ask questions latter. They also both gather a "crew" or "team" and make friends of their enemies. If you couldn't help but love one of these main characters, I would take a look at the other.
In the year 200X, World War III began. Special bombs destroyed parts of cities such as Tokyo, leaving decimation in their wake. Decades later, ground zero in Tokyo – an isolated section known as the Black Spot – remains an enigma. Its residents known as Needless possess strange powers such as the ability to control fire or telekinesis, and are constantly hunted down by Simeon, a large pharmaceutical company with sinister motives and Needless of their own to do their bidding. Young Cruz is part of a resistance to fight against Simeon and its Needless figurehead leader, Adam Arclight; but after the resistance is brutally killed by Simeon’s minions, he finds himself saved by a motley crew: Professor Gido, scantily-clad Eve and badass Blade. Together, the gang fends off Simeon’s attacks and tries to discover the truth behind the corporation’s actions. What is Simeon really after, and why do they desperately want to find Fragments?
In a sand-swept land of caravans, brigands and adventurers, legends tell of the ominous dungeon towers that suddenly appeared 14 years ago. It's said that by clearing one of these prisons, you can obtain treasure beyond your wildest dreams, and even form a contract with magical genies of immense power - assuming you make it out alive. In this world, Alibaba is a young rogue who wants nothing more than to get rich by clearing all of the world's dungeons, starting with the nearby tower Amon; Aladdin is a curious young boy with a magical flute and a hidden ability; and Morgiana is a slave who can't escape her chains. As their fates intertwine, the three find themselves wandering the land, battling powerful enemies, and taking a stand against powerful forces that seek to corrupt the weak and innocent.