The Gomu Gomu no Mi is an incredibly important Devil Fruit in the One Piece world and also the very first one that was introduced to the fans in the story, right at the beginning, when Luffy ate it. Ever since then, the Gomu Gomu no Mi has been central to the story of One Piece. This is the main power source of Luffy, the protagonist of the series, and he has been using it incredibly well over the years.