One Piece started as three one-shot stories entitled Romance Dawn—which would later be used as the title for One Piece's first chapter and volume. The two one-shots featured the character of Luffy, and included elements that would later appear in the main series. The first of these short stories was published in August 1996 in a special issue of Shōnen Jump and later in One Piece Red. The second was published in the 41st issue of Shōnen Jump in 1996 and reprinted 1998 in Oda's short story collection, Wanted!.
Oda originally planned One Piece to last five years, and he had already planned out the ending, but he found himself enjoying the story too much to end it in that amount of time and now has no idea how long it will take to reach that point. Nevertheless, the author states, as of July 2007, that the ending will still be the one he had decided on from the beginning and he is committed to seeing it through to the end, no matter how many years it takes.
When creating a Devil Fruit, Oda thinks of something that would fulfill a human desire; he added that he does not see why he would draw a Devil Fruit unless the fruit's appearance would entice one to eat it. The names of many special attacks and other concepts in the manga consist of a form of punning, in which phrases written in kanji are paired with an idiosyncratic reading. The names of Luffy, Sanji, Chopper, Robin, and Franky's techniques are often mixed with other languages, and the names of a number of Zoro's sword techniques are designed as jokes; for example, some of them look fearsome when read by sight but sound like kinds of food when read aloud. Eisaku Inoue, the animation director, has said that the creators did not use these kanji readings in the anime since they "might have cut down the laughs by about half." Nevertheless, Konosuke Uda, the director, said that he believes that the creators "made the anime pretty close to the manga."
Oda was "sensitive" about how it would be translated. The English version of the One Piece manga in many instances uses one onomatopoeia for multiple onomatopoeia used in the Japanese version. For instance, "saaa" (the sound of light rain, close to a mist) and "zaaa" (the sound of pouring rain) are both translated as "fshhhhhhh."