During the Arabasta arc of the One Piece series, Princess Vivi temporarily bestowed the title “Mr. Bushido” upon Roronoa Zoro. This was largely a playful, ironic nickname. Vivi, unfamiliar with the concept of “bushido” beyond a superficial understanding, associated it with a general idea of samurai ethics, loyalty, and swordsmanship. She saw these qualities reflected in Zoros behavior and fighting style, even though his actual code is more pragmatic and less traditionally bound by such a rigid framework.
The significance of this moniker lies in its highlighting of Zoro’s perceived honor and strength. Although Zoro doesn’t adhere to a strict bushido code, his unwavering commitment to Luffy, his dedication to his own strength, and his willingness to sacrifice for his crew align loosely with some of the values associated with the samurai tradition. It’s a cultural misapplication that is nonetheless endearing due to Vivi’s naivet and Zoro’s general disinterest in clarifying the matter. It serves to further characterize Vivis kindhearted, albeit sometimes airheaded, nature and provides a lighthearted moment within a serious storyline. The application of such a title to a character who isn’t consciously striving to embody it creates a humorous contrast.
