Eiichiro Oda is the author of One Piece, the best-selling manga series of all time. It has sold over 500 million copies, which is more than twice what Naruto has sold. It is worth noting that Naruto was supposed to be the closest thing to One Piece, but the gap proves otherwise. One Piece has been wildly successful because of the quality of writing. Oda has cleverly created an intricate world in which smaller things are just as important as big ones.